]> git.bitcoin.ninja Git - rust-lightning/blob - lightning/src/ln/chan_utils.rs
8dc31115f96d7dc93cdbc6d9b0cf5cd4e8d0c366
[rust-lightning] / lightning / src / ln / chan_utils.rs
1 // This file is Copyright its original authors, visible in version control
2 // history.
3 //
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
8 // licenses.
9
10 //! Various utilities for building scripts and deriving keys related to channels. These are
11 //! largely of interest for those implementing the traits on [`crate::sign`] by hand.
12
13 use bitcoin::blockdata::script::{Script, ScriptBuf, Builder};
14 use bitcoin::blockdata::opcodes;
15 use bitcoin::blockdata::transaction::{TxIn,TxOut,OutPoint,Transaction};
16 use bitcoin::sighash;
17 use bitcoin::sighash::EcdsaSighashType;
18 use bitcoin::address::Payload;
19
20 use bitcoin::hashes::{Hash, HashEngine};
21 use bitcoin::hashes::sha256::Hash as Sha256;
22 use bitcoin::hashes::ripemd160::Hash as Ripemd160;
23 use bitcoin::hash_types::{Txid, PubkeyHash, WPubkeyHash};
24
25 use crate::chain::chaininterface::fee_for_weight;
26 use crate::chain::package::WEIGHT_REVOKED_OUTPUT;
27 use crate::sign::EntropySource;
28 use crate::ln::{PaymentHash, PaymentPreimage};
29 use crate::ln::msgs::DecodeError;
30 use crate::util::ser::{Readable, RequiredWrapper, Writeable, Writer};
31 use crate::util::transaction_utils;
32
33 use bitcoin::blockdata::locktime::absolute::LockTime;
34 use bitcoin::secp256k1::{SecretKey, PublicKey, Scalar};
35 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature, Message};
36 use bitcoin::{secp256k1, Sequence, Witness};
37 use bitcoin::PublicKey as BitcoinPublicKey;
38
39 use crate::io;
40 use crate::prelude::*;
41 use core::cmp;
42 use crate::ln::chan_utils;
43 use crate::util::transaction_utils::sort_outputs;
44 use crate::ln::channel::{INITIAL_COMMITMENT_NUMBER, ANCHOR_OUTPUT_VALUE_SATOSHI};
45 use core::ops::Deref;
46 use crate::chain;
47 use crate::ln::features::ChannelTypeFeatures;
48 use crate::util::crypto::{sign, sign_with_aux_rand};
49
50 /// Maximum number of one-way in-flight HTLC (protocol-level value).
51 pub const MAX_HTLCS: u16 = 483;
52 /// The weight of a BIP141 witnessScript for a BOLT3's "offered HTLC output" on a commitment transaction, non-anchor variant.
53 pub const OFFERED_HTLC_SCRIPT_WEIGHT: usize = 133;
54 /// The weight of a BIP141 witnessScript for a BOLT3's "offered HTLC output" on a commitment transaction, anchor variant.
55 pub const OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS: usize = 136;
56
57 /// The weight of a BIP141 witnessScript for a BOLT3's "received HTLC output" can vary in function of its CLTV argument value.
58 /// We define a range that encompasses both its non-anchors and anchors variants.
59 pub(crate) const MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 136;
60 /// The weight of a BIP141 witnessScript for a BOLT3's "received HTLC output" can vary in function of its CLTV argument value.
61 /// We define a range that encompasses both its non-anchors and anchors variants.
62 /// This is the maximum post-anchor value.
63 pub const MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT: usize = 143;
64
65 /// The upper bound weight of an anchor input.
66 pub const ANCHOR_INPUT_WITNESS_WEIGHT: u64 = 116;
67 /// The upper bound weight of an HTLC timeout input from a commitment transaction with anchor
68 /// outputs.
69 pub const HTLC_TIMEOUT_INPUT_ANCHOR_WITNESS_WEIGHT: u64 = 288;
70 /// The upper bound weight of an HTLC success input from a commitment transaction with anchor
71 /// outputs.
72 pub const HTLC_SUCCESS_INPUT_ANCHOR_WITNESS_WEIGHT: u64 = 327;
73
74 /// Gets the weight for an HTLC-Success transaction.
75 #[inline]
76 pub fn htlc_success_tx_weight(channel_type_features: &ChannelTypeFeatures) -> u64 {
77         const HTLC_SUCCESS_TX_WEIGHT: u64 = 703;
78         const HTLC_SUCCESS_ANCHOR_TX_WEIGHT: u64 = 706;
79         if channel_type_features.supports_anchors_zero_fee_htlc_tx() { HTLC_SUCCESS_ANCHOR_TX_WEIGHT } else { HTLC_SUCCESS_TX_WEIGHT }
80 }
81
82 /// Gets the weight for an HTLC-Timeout transaction.
83 #[inline]
84 pub fn htlc_timeout_tx_weight(channel_type_features: &ChannelTypeFeatures) -> u64 {
85         const HTLC_TIMEOUT_TX_WEIGHT: u64 = 663;
86         const HTLC_TIMEOUT_ANCHOR_TX_WEIGHT: u64 = 666;
87         if channel_type_features.supports_anchors_zero_fee_htlc_tx() { HTLC_TIMEOUT_ANCHOR_TX_WEIGHT } else { HTLC_TIMEOUT_TX_WEIGHT }
88 }
89
90 /// Describes the type of HTLC claim as determined by analyzing the witness.
91 #[derive(PartialEq, Eq)]
92 pub enum HTLCClaim {
93         /// Claims an offered output on a commitment transaction through the timeout path.
94         OfferedTimeout,
95         /// Claims an offered output on a commitment transaction through the success path.
96         OfferedPreimage,
97         /// Claims an accepted output on a commitment transaction through the timeout path.
98         AcceptedTimeout,
99         /// Claims an accepted output on a commitment transaction through the success path.
100         AcceptedPreimage,
101         /// Claims an offered/accepted output on a commitment transaction through the revocation path.
102         Revocation,
103 }
104
105 impl HTLCClaim {
106         /// Check if a given input witness attempts to claim a HTLC.
107         pub fn from_witness(witness: &Witness) -> Option<Self> {
108                 debug_assert_eq!(OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS, MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT);
109                 if witness.len() < 2 {
110                         return None;
111                 }
112                 let witness_script = witness.last().unwrap();
113                 let second_to_last = witness.second_to_last().unwrap();
114                 if witness_script.len() == OFFERED_HTLC_SCRIPT_WEIGHT {
115                         if witness.len() == 3 && second_to_last.len() == 33 {
116                                 // <revocation sig> <revocationpubkey> <witness_script>
117                                 Some(Self::Revocation)
118                         } else if witness.len() == 3 && second_to_last.len() == 32 {
119                                 // <remotehtlcsig> <payment_preimage> <witness_script>
120                                 Some(Self::OfferedPreimage)
121                         } else if witness.len() == 5 && second_to_last.len() == 0 {
122                                 // 0 <remotehtlcsig> <localhtlcsig> <> <witness_script>
123                                 Some(Self::OfferedTimeout)
124                         } else {
125                                 None
126                         }
127                 } else if witness_script.len() == OFFERED_HTLC_SCRIPT_WEIGHT_ANCHORS {
128                         // It's possible for the weight of `offered_htlc_script` and `accepted_htlc_script` to
129                         // match so we check for both here.
130                         if witness.len() == 3 && second_to_last.len() == 33 {
131                                 // <revocation sig> <revocationpubkey> <witness_script>
132                                 Some(Self::Revocation)
133                         } else if witness.len() == 3 && second_to_last.len() == 32 {
134                                 // <remotehtlcsig> <payment_preimage> <witness_script>
135                                 Some(Self::OfferedPreimage)
136                         } else if witness.len() == 5 && second_to_last.len() == 0 {
137                                 // 0 <remotehtlcsig> <localhtlcsig> <> <witness_script>
138                                 Some(Self::OfferedTimeout)
139                         } else if witness.len() == 3 && second_to_last.len() == 0 {
140                                 // <remotehtlcsig> <> <witness_script>
141                                 Some(Self::AcceptedTimeout)
142                         } else if witness.len() == 5 && second_to_last.len() == 32 {
143                                 // 0 <remotehtlcsig> <localhtlcsig> <payment_preimage> <witness_script>
144                                 Some(Self::AcceptedPreimage)
145                         } else {
146                                 None
147                         }
148                 } else if witness_script.len() > MIN_ACCEPTED_HTLC_SCRIPT_WEIGHT &&
149                         witness_script.len() <= MAX_ACCEPTED_HTLC_SCRIPT_WEIGHT {
150                         // Handle remaining range of ACCEPTED_HTLC_SCRIPT_WEIGHT.
151                         if witness.len() == 3 && second_to_last.len() == 33 {
152                                 // <revocation sig> <revocationpubkey> <witness_script>
153                                 Some(Self::Revocation)
154                         } else if witness.len() == 3 && second_to_last.len() == 0 {
155                                 // <remotehtlcsig> <> <witness_script>
156                                 Some(Self::AcceptedTimeout)
157                         } else if witness.len() == 5 && second_to_last.len() == 32 {
158                                 // 0 <remotehtlcsig> <localhtlcsig> <payment_preimage> <witness_script>
159                                 Some(Self::AcceptedPreimage)
160                         } else {
161                                 None
162                         }
163                 } else {
164                         None
165                 }
166         }
167 }
168
169 // Various functions for key derivation and transaction creation for use within channels. Primarily
170 // used in Channel and ChannelMonitor.
171
172 /// Build the commitment secret from the seed and the commitment number
173 pub fn build_commitment_secret(commitment_seed: &[u8; 32], idx: u64) -> [u8; 32] {
174         let mut res: [u8; 32] = commitment_seed.clone();
175         for i in 0..48 {
176                 let bitpos = 47 - i;
177                 if idx & (1 << bitpos) == (1 << bitpos) {
178                         res[bitpos / 8] ^= 1 << (bitpos & 7);
179                         res = Sha256::hash(&res).to_byte_array();
180                 }
181         }
182         res
183 }
184
185 /// Build a closing transaction
186 pub fn build_closing_transaction(to_holder_value_sat: u64, to_counterparty_value_sat: u64, to_holder_script: ScriptBuf, to_counterparty_script: ScriptBuf, funding_outpoint: OutPoint) -> Transaction {
187         let txins = {
188                 let mut ins: Vec<TxIn> = Vec::new();
189                 ins.push(TxIn {
190                         previous_output: funding_outpoint,
191                         script_sig: ScriptBuf::new(),
192                         sequence: Sequence::MAX,
193                         witness: Witness::new(),
194                 });
195                 ins
196         };
197
198         let mut txouts: Vec<(TxOut, ())> = Vec::new();
199
200         if to_counterparty_value_sat > 0 {
201                 txouts.push((TxOut {
202                         script_pubkey: to_counterparty_script,
203                         value: to_counterparty_value_sat
204                 }, ()));
205         }
206
207         if to_holder_value_sat > 0 {
208                 txouts.push((TxOut {
209                         script_pubkey: to_holder_script,
210                         value: to_holder_value_sat
211                 }, ()));
212         }
213
214         transaction_utils::sort_outputs(&mut txouts, |_, _| { cmp::Ordering::Equal }); // Ordering doesnt matter if they used our pubkey...
215
216         let mut outputs: Vec<TxOut> = Vec::new();
217         for out in txouts.drain(..) {
218                 outputs.push(out.0);
219         }
220
221         Transaction {
222                 version: 2,
223                 lock_time: LockTime::ZERO,
224                 input: txins,
225                 output: outputs,
226         }
227 }
228
229 /// Implements the per-commitment secret storage scheme from
230 /// [BOLT 3](https://github.com/lightning/bolts/blob/dcbf8583976df087c79c3ce0b535311212e6812d/03-transactions.md#efficient-per-commitment-secret-storage).
231 ///
232 /// Allows us to keep track of all of the revocation secrets of our counterparty in just 50*32 bytes
233 /// or so.
234 #[derive(Clone)]
235 pub struct CounterpartyCommitmentSecrets {
236         old_secrets: [([u8; 32], u64); 49],
237 }
238
239 impl Eq for CounterpartyCommitmentSecrets {}
240 impl PartialEq for CounterpartyCommitmentSecrets {
241         fn eq(&self, other: &Self) -> bool {
242                 for (&(ref secret, ref idx), &(ref o_secret, ref o_idx)) in self.old_secrets.iter().zip(other.old_secrets.iter()) {
243                         if secret != o_secret || idx != o_idx {
244                                 return false
245                         }
246                 }
247                 true
248         }
249 }
250
251 impl CounterpartyCommitmentSecrets {
252         /// Creates a new empty `CounterpartyCommitmentSecrets` structure.
253         pub fn new() -> Self {
254                 Self { old_secrets: [([0; 32], 1 << 48); 49], }
255         }
256
257         #[inline]
258         fn place_secret(idx: u64) -> u8 {
259                 for i in 0..48 {
260                         if idx & (1 << i) == (1 << i) {
261                                 return i
262                         }
263                 }
264                 48
265         }
266
267         /// Returns the minimum index of all stored secrets. Note that indexes start
268         /// at 1 << 48 and get decremented by one for each new secret.
269         pub fn get_min_seen_secret(&self) -> u64 {
270                 //TODO This can be optimized?
271                 let mut min = 1 << 48;
272                 for &(_, idx) in self.old_secrets.iter() {
273                         if idx < min {
274                                 min = idx;
275                         }
276                 }
277                 min
278         }
279
280         #[inline]
281         fn derive_secret(secret: [u8; 32], bits: u8, idx: u64) -> [u8; 32] {
282                 let mut res: [u8; 32] = secret;
283                 for i in 0..bits {
284                         let bitpos = bits - 1 - i;
285                         if idx & (1 << bitpos) == (1 << bitpos) {
286                                 res[(bitpos / 8) as usize] ^= 1 << (bitpos & 7);
287                                 res = Sha256::hash(&res).to_byte_array();
288                         }
289                 }
290                 res
291         }
292
293         /// Inserts the `secret` at `idx`. Returns `Ok(())` if the secret
294         /// was generated in accordance with BOLT 3 and is consistent with previous secrets.
295         pub fn provide_secret(&mut self, idx: u64, secret: [u8; 32]) -> Result<(), ()> {
296                 let pos = Self::place_secret(idx);
297                 for i in 0..pos {
298                         let (old_secret, old_idx) = self.old_secrets[i as usize];
299                         if Self::derive_secret(secret, pos, old_idx) != old_secret {
300                                 return Err(());
301                         }
302                 }
303                 if self.get_min_seen_secret() <= idx {
304                         return Ok(());
305                 }
306                 self.old_secrets[pos as usize] = (secret, idx);
307                 Ok(())
308         }
309
310         /// Returns the secret at `idx`.
311         /// Returns `None` if `idx` is < [`CounterpartyCommitmentSecrets::get_min_seen_secret`].
312         pub fn get_secret(&self, idx: u64) -> Option<[u8; 32]> {
313                 for i in 0..self.old_secrets.len() {
314                         if (idx & (!((1 << i) - 1))) == self.old_secrets[i].1 {
315                                 return Some(Self::derive_secret(self.old_secrets[i].0, i as u8, idx))
316                         }
317                 }
318                 assert!(idx < self.get_min_seen_secret());
319                 None
320         }
321 }
322
323 impl Writeable for CounterpartyCommitmentSecrets {
324         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
325                 for &(ref secret, ref idx) in self.old_secrets.iter() {
326                         writer.write_all(secret)?;
327                         writer.write_all(&idx.to_be_bytes())?;
328                 }
329                 write_tlv_fields!(writer, {});
330                 Ok(())
331         }
332 }
333 impl Readable for CounterpartyCommitmentSecrets {
334         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
335                 let mut old_secrets = [([0; 32], 1 << 48); 49];
336                 for &mut (ref mut secret, ref mut idx) in old_secrets.iter_mut() {
337                         *secret = Readable::read(reader)?;
338                         *idx = Readable::read(reader)?;
339                 }
340                 read_tlv_fields!(reader, {});
341                 Ok(Self { old_secrets })
342         }
343 }
344
345 /// Derives a per-commitment-transaction private key (eg an htlc key or delayed_payment key)
346 /// from the base secret and the per_commitment_point.
347 pub fn derive_private_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_secret: &SecretKey) -> SecretKey {
348         let mut sha = Sha256::engine();
349         sha.input(&per_commitment_point.serialize());
350         sha.input(&PublicKey::from_secret_key(&secp_ctx, &base_secret).serialize());
351         let res = Sha256::from_engine(sha).to_byte_array();
352
353         base_secret.clone().add_tweak(&Scalar::from_be_bytes(res).unwrap())
354                 .expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak contains the hash of the key.")
355 }
356
357 /// Derives a per-commitment-transaction public key (eg an htlc key or a delayed_payment key)
358 /// from the base point and the per_commitment_key. This is the public equivalent of
359 /// derive_private_key - using only public keys to derive a public key instead of private keys.
360 pub fn derive_public_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, base_point: &PublicKey) -> PublicKey {
361         let mut sha = Sha256::engine();
362         sha.input(&per_commitment_point.serialize());
363         sha.input(&base_point.serialize());
364         let res = Sha256::from_engine(sha).to_byte_array();
365
366         let hashkey = PublicKey::from_secret_key(&secp_ctx,
367                 &SecretKey::from_slice(&res).expect("Hashes should always be valid keys unless SHA-256 is broken"));
368         base_point.combine(&hashkey)
369                 .expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak contains the hash of the key.")
370 }
371
372 /// Derives a per-commitment-transaction revocation key from its constituent parts.
373 ///
374 /// Only the cheating participant owns a valid witness to propagate a revoked
375 /// commitment transaction, thus per_commitment_secret always come from cheater
376 /// and revocation_base_secret always come from punisher, which is the broadcaster
377 /// of the transaction spending with this key knowledge.
378 pub fn derive_private_revocation_key<T: secp256k1::Signing>(secp_ctx: &Secp256k1<T>,
379         per_commitment_secret: &SecretKey, countersignatory_revocation_base_secret: &SecretKey)
380 -> SecretKey {
381         let countersignatory_revocation_base_point = PublicKey::from_secret_key(&secp_ctx, &countersignatory_revocation_base_secret);
382         let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
383
384         let rev_append_commit_hash_key = {
385                 let mut sha = Sha256::engine();
386                 sha.input(&countersignatory_revocation_base_point.serialize());
387                 sha.input(&per_commitment_point.serialize());
388
389                 Sha256::from_engine(sha).to_byte_array()
390         };
391         let commit_append_rev_hash_key = {
392                 let mut sha = Sha256::engine();
393                 sha.input(&per_commitment_point.serialize());
394                 sha.input(&countersignatory_revocation_base_point.serialize());
395
396                 Sha256::from_engine(sha).to_byte_array()
397         };
398
399         let countersignatory_contrib = countersignatory_revocation_base_secret.clone().mul_tweak(&Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())
400                 .expect("Multiplying a secret key by a hash is expected to never fail per secp256k1 docs");
401         let broadcaster_contrib = per_commitment_secret.clone().mul_tweak(&Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())
402                 .expect("Multiplying a secret key by a hash is expected to never fail per secp256k1 docs");
403         countersignatory_contrib.add_tweak(&Scalar::from_be_bytes(broadcaster_contrib.secret_bytes()).unwrap())
404                 .expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak commits to the key.")
405 }
406
407 /// Derives a per-commitment-transaction revocation public key from its constituent parts. This is
408 /// the public equivalend of derive_private_revocation_key - using only public keys to derive a
409 /// public key instead of private keys.
410 ///
411 /// Only the cheating participant owns a valid witness to propagate a revoked
412 /// commitment transaction, thus per_commitment_point always come from cheater
413 /// and revocation_base_point always come from punisher, which is the broadcaster
414 /// of the transaction spending with this key knowledge.
415 ///
416 /// Note that this is infallible iff we trust that at least one of the two input keys are randomly
417 /// generated (ie our own).
418 pub fn derive_public_revocation_key<T: secp256k1::Verification>(secp_ctx: &Secp256k1<T>,
419         per_commitment_point: &PublicKey, countersignatory_revocation_base_point: &PublicKey)
420 -> PublicKey {
421         let rev_append_commit_hash_key = {
422                 let mut sha = Sha256::engine();
423                 sha.input(&countersignatory_revocation_base_point.serialize());
424                 sha.input(&per_commitment_point.serialize());
425
426                 Sha256::from_engine(sha).to_byte_array()
427         };
428         let commit_append_rev_hash_key = {
429                 let mut sha = Sha256::engine();
430                 sha.input(&per_commitment_point.serialize());
431                 sha.input(&countersignatory_revocation_base_point.serialize());
432
433                 Sha256::from_engine(sha).to_byte_array()
434         };
435
436         let countersignatory_contrib = countersignatory_revocation_base_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(rev_append_commit_hash_key).unwrap())
437                 .expect("Multiplying a valid public key by a hash is expected to never fail per secp256k1 docs");
438         let broadcaster_contrib = per_commitment_point.clone().mul_tweak(&secp_ctx, &Scalar::from_be_bytes(commit_append_rev_hash_key).unwrap())
439                 .expect("Multiplying a valid public key by a hash is expected to never fail per secp256k1 docs");
440         countersignatory_contrib.combine(&broadcaster_contrib)
441                 .expect("Addition only fails if the tweak is the inverse of the key. This is not possible when the tweak commits to the key.")
442 }
443
444 /// The set of public keys which are used in the creation of one commitment transaction.
445 /// These are derived from the channel base keys and per-commitment data.
446 ///
447 /// A broadcaster key is provided from potential broadcaster of the computed transaction.
448 /// A countersignatory key is coming from a protocol participant unable to broadcast the
449 /// transaction.
450 ///
451 /// These keys are assumed to be good, either because the code derived them from
452 /// channel basepoints via the new function, or they were obtained via
453 /// CommitmentTransaction.trust().keys() because we trusted the source of the
454 /// pre-calculated keys.
455 #[derive(PartialEq, Eq, Clone, Debug)]
456 pub struct TxCreationKeys {
457         /// The broadcaster's per-commitment public key which was used to derive the other keys.
458         pub per_commitment_point: PublicKey,
459         /// The revocation key which is used to allow the broadcaster of the commitment
460         /// transaction to provide their counterparty the ability to punish them if they broadcast
461         /// an old state.
462         pub revocation_key: PublicKey,
463         /// Broadcaster's HTLC Key
464         pub broadcaster_htlc_key: PublicKey,
465         /// Countersignatory's HTLC Key
466         pub countersignatory_htlc_key: PublicKey,
467         /// Broadcaster's Payment Key (which isn't allowed to be spent from for some delay)
468         pub broadcaster_delayed_payment_key: PublicKey,
469 }
470
471 impl_writeable_tlv_based!(TxCreationKeys, {
472         (0, per_commitment_point, required),
473         (2, revocation_key, required),
474         (4, broadcaster_htlc_key, required),
475         (6, countersignatory_htlc_key, required),
476         (8, broadcaster_delayed_payment_key, required),
477 });
478
479 /// One counterparty's public keys which do not change over the life of a channel.
480 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
481 pub struct ChannelPublicKeys {
482         /// The public key which is used to sign all commitment transactions, as it appears in the
483         /// on-chain channel lock-in 2-of-2 multisig output.
484         pub funding_pubkey: PublicKey,
485         /// The base point which is used (with derive_public_revocation_key) to derive per-commitment
486         /// revocation keys. This is combined with the per-commitment-secret generated by the
487         /// counterparty to create a secret which the counterparty can reveal to revoke previous
488         /// states.
489         pub revocation_basepoint: PublicKey,
490         /// The public key on which the non-broadcaster (ie the countersignatory) receives an immediately
491         /// spendable primary channel balance on the broadcaster's commitment transaction. This key is
492         /// static across every commitment transaction.
493         pub payment_point: PublicKey,
494         /// The base point which is used (with derive_public_key) to derive a per-commitment payment
495         /// public key which receives non-HTLC-encumbered funds which are only available for spending
496         /// after some delay (or can be claimed via the revocation path).
497         pub delayed_payment_basepoint: PublicKey,
498         /// The base point which is used (with derive_public_key) to derive a per-commitment public key
499         /// which is used to encumber HTLC-in-flight outputs.
500         pub htlc_basepoint: PublicKey,
501 }
502
503 impl_writeable_tlv_based!(ChannelPublicKeys, {
504         (0, funding_pubkey, required),
505         (2, revocation_basepoint, required),
506         (4, payment_point, required),
507         (6, delayed_payment_basepoint, required),
508         (8, htlc_basepoint, required),
509 });
510
511 impl TxCreationKeys {
512         /// Create per-state keys from channel base points and the per-commitment point.
513         /// Key set is asymmetric and can't be used as part of counter-signatory set of transactions.
514         pub fn derive_new<T: secp256k1::Signing + secp256k1::Verification>(secp_ctx: &Secp256k1<T>, per_commitment_point: &PublicKey, broadcaster_delayed_payment_base: &PublicKey, broadcaster_htlc_base: &PublicKey, countersignatory_revocation_base: &PublicKey, countersignatory_htlc_base: &PublicKey) -> TxCreationKeys {
515                 TxCreationKeys {
516                         per_commitment_point: per_commitment_point.clone(),
517                         revocation_key: derive_public_revocation_key(&secp_ctx, &per_commitment_point, &countersignatory_revocation_base),
518                         broadcaster_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_htlc_base),
519                         countersignatory_htlc_key: derive_public_key(&secp_ctx, &per_commitment_point, &countersignatory_htlc_base),
520                         broadcaster_delayed_payment_key: derive_public_key(&secp_ctx, &per_commitment_point, &broadcaster_delayed_payment_base),
521                 }
522         }
523
524         /// Generate per-state keys from channel static keys.
525         /// Key set is asymmetric and can't be used as part of counter-signatory set of transactions.
526         pub fn from_channel_static_keys<T: secp256k1::Signing + secp256k1::Verification>(per_commitment_point: &PublicKey, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1<T>) -> TxCreationKeys {
527                 TxCreationKeys::derive_new(
528                         &secp_ctx,
529                         &per_commitment_point,
530                         &broadcaster_keys.delayed_payment_basepoint,
531                         &broadcaster_keys.htlc_basepoint,
532                         &countersignatory_keys.revocation_basepoint,
533                         &countersignatory_keys.htlc_basepoint,
534                 )
535         }
536 }
537
538 /// The maximum length of a script returned by get_revokeable_redeemscript.
539 // Calculated as 6 bytes of opcodes, 1 byte push plus 2 bytes for contest_delay, and two public
540 // keys of 33 bytes (+ 1 push).
541 pub const REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH: usize = 6 + 3 + 34*2;
542
543 /// A script either spendable by the revocation
544 /// key or the broadcaster_delayed_payment_key and satisfying the relative-locktime OP_CSV constrain.
545 /// Encumbering a `to_holder` output on a commitment transaction or 2nd-stage HTLC transactions.
546 pub fn get_revokeable_redeemscript(revocation_key: &PublicKey, contest_delay: u16, broadcaster_delayed_payment_key: &PublicKey) -> ScriptBuf {
547         let res = Builder::new().push_opcode(opcodes::all::OP_IF)
548                       .push_slice(&revocation_key.serialize())
549                       .push_opcode(opcodes::all::OP_ELSE)
550                       .push_int(contest_delay as i64)
551                       .push_opcode(opcodes::all::OP_CSV)
552                       .push_opcode(opcodes::all::OP_DROP)
553                       .push_slice(&broadcaster_delayed_payment_key.serialize())
554                       .push_opcode(opcodes::all::OP_ENDIF)
555                       .push_opcode(opcodes::all::OP_CHECKSIG)
556                       .into_script();
557         debug_assert!(res.len() <= REVOKEABLE_REDEEMSCRIPT_MAX_LENGTH);
558         res
559 }
560
561 /// Returns the script for the counterparty's output on a holder's commitment transaction based on
562 /// the channel type.
563 pub fn get_counterparty_payment_script(channel_type_features: &ChannelTypeFeatures, payment_key: &PublicKey) -> ScriptBuf {
564         if channel_type_features.supports_anchors_zero_fee_htlc_tx() {
565                 get_to_countersignatory_with_anchors_redeemscript(payment_key).to_v0_p2wsh()
566         } else {
567                 ScriptBuf::new_v0_p2wpkh(&WPubkeyHash::hash(&payment_key.serialize()))
568         }
569 }
570
571 /// Information about an HTLC as it appears in a commitment transaction
572 #[derive(Clone, Debug, PartialEq, Eq)]
573 pub struct HTLCOutputInCommitment {
574         /// Whether the HTLC was "offered" (ie outbound in relation to this commitment transaction).
575         /// Note that this is not the same as whether it is ountbound *from us*. To determine that you
576         /// need to compare this value to whether the commitment transaction in question is that of
577         /// the counterparty or our own.
578         pub offered: bool,
579         /// The value, in msat, of the HTLC. The value as it appears in the commitment transaction is
580         /// this divided by 1000.
581         pub amount_msat: u64,
582         /// The CLTV lock-time at which this HTLC expires.
583         pub cltv_expiry: u32,
584         /// The hash of the preimage which unlocks this HTLC.
585         pub payment_hash: PaymentHash,
586         /// The position within the commitment transactions' outputs. This may be None if the value is
587         /// below the dust limit (in which case no output appears in the commitment transaction and the
588         /// value is spent to additional transaction fees).
589         pub transaction_output_index: Option<u32>,
590 }
591
592 impl_writeable_tlv_based!(HTLCOutputInCommitment, {
593         (0, offered, required),
594         (2, amount_msat, required),
595         (4, cltv_expiry, required),
596         (6, payment_hash, required),
597         (8, transaction_output_index, option),
598 });
599
600 #[inline]
601 pub(crate) fn get_htlc_redeemscript_with_explicit_keys(htlc: &HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures, broadcaster_htlc_key: &PublicKey, countersignatory_htlc_key: &PublicKey, revocation_key: &PublicKey) -> ScriptBuf {
602         let payment_hash160 = Ripemd160::hash(&htlc.payment_hash.0[..]).to_byte_array();
603         if htlc.offered {
604                 let mut bldr = Builder::new().push_opcode(opcodes::all::OP_DUP)
605                               .push_opcode(opcodes::all::OP_HASH160)
606                               .push_slice(PubkeyHash::hash(&revocation_key.serialize()))
607                               .push_opcode(opcodes::all::OP_EQUAL)
608                               .push_opcode(opcodes::all::OP_IF)
609                               .push_opcode(opcodes::all::OP_CHECKSIG)
610                               .push_opcode(opcodes::all::OP_ELSE)
611                               .push_slice(countersignatory_htlc_key.serialize())
612                               .push_opcode(opcodes::all::OP_SWAP)
613                               .push_opcode(opcodes::all::OP_SIZE)
614                               .push_int(32)
615                               .push_opcode(opcodes::all::OP_EQUAL)
616                               .push_opcode(opcodes::all::OP_NOTIF)
617                               .push_opcode(opcodes::all::OP_DROP)
618                               .push_int(2)
619                               .push_opcode(opcodes::all::OP_SWAP)
620                               .push_slice(broadcaster_htlc_key.serialize())
621                               .push_int(2)
622                               .push_opcode(opcodes::all::OP_CHECKMULTISIG)
623                               .push_opcode(opcodes::all::OP_ELSE)
624                               .push_opcode(opcodes::all::OP_HASH160)
625                               .push_slice(&payment_hash160)
626                               .push_opcode(opcodes::all::OP_EQUALVERIFY)
627                               .push_opcode(opcodes::all::OP_CHECKSIG)
628                               .push_opcode(opcodes::all::OP_ENDIF);
629                 if channel_type_features.supports_anchors_zero_fee_htlc_tx() {
630                         bldr = bldr.push_opcode(opcodes::all::OP_PUSHNUM_1)
631                                 .push_opcode(opcodes::all::OP_CSV)
632                                 .push_opcode(opcodes::all::OP_DROP);
633                 }
634                 bldr.push_opcode(opcodes::all::OP_ENDIF)
635                         .into_script()
636         } else {
637                         let mut bldr = Builder::new().push_opcode(opcodes::all::OP_DUP)
638                               .push_opcode(opcodes::all::OP_HASH160)
639                               .push_slice(PubkeyHash::hash(&revocation_key.serialize()))
640                               .push_opcode(opcodes::all::OP_EQUAL)
641                               .push_opcode(opcodes::all::OP_IF)
642                               .push_opcode(opcodes::all::OP_CHECKSIG)
643                               .push_opcode(opcodes::all::OP_ELSE)
644                               .push_slice(countersignatory_htlc_key.serialize())
645                               .push_opcode(opcodes::all::OP_SWAP)
646                               .push_opcode(opcodes::all::OP_SIZE)
647                               .push_int(32)
648                               .push_opcode(opcodes::all::OP_EQUAL)
649                               .push_opcode(opcodes::all::OP_IF)
650                               .push_opcode(opcodes::all::OP_HASH160)
651                               .push_slice(&payment_hash160)
652                               .push_opcode(opcodes::all::OP_EQUALVERIFY)
653                               .push_int(2)
654                               .push_opcode(opcodes::all::OP_SWAP)
655                               .push_slice(broadcaster_htlc_key.serialize())
656                               .push_int(2)
657                               .push_opcode(opcodes::all::OP_CHECKMULTISIG)
658                               .push_opcode(opcodes::all::OP_ELSE)
659                               .push_opcode(opcodes::all::OP_DROP)
660                               .push_int(htlc.cltv_expiry as i64)
661                               .push_opcode(opcodes::all::OP_CLTV)
662                               .push_opcode(opcodes::all::OP_DROP)
663                               .push_opcode(opcodes::all::OP_CHECKSIG)
664                               .push_opcode(opcodes::all::OP_ENDIF);
665                 if channel_type_features.supports_anchors_zero_fee_htlc_tx() {
666                         bldr = bldr.push_opcode(opcodes::all::OP_PUSHNUM_1)
667                                 .push_opcode(opcodes::all::OP_CSV)
668                                 .push_opcode(opcodes::all::OP_DROP);
669                 }
670                 bldr.push_opcode(opcodes::all::OP_ENDIF)
671                         .into_script()
672         }
673 }
674
675 /// Gets the witness redeemscript for an HTLC output in a commitment transaction. Note that htlc
676 /// does not need to have its previous_output_index filled.
677 #[inline]
678 pub fn get_htlc_redeemscript(htlc: &HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures, keys: &TxCreationKeys) -> ScriptBuf {
679         get_htlc_redeemscript_with_explicit_keys(htlc, channel_type_features, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key)
680 }
681
682 /// Gets the redeemscript for a funding output from the two funding public keys.
683 /// Note that the order of funding public keys does not matter.
684 pub fn make_funding_redeemscript(broadcaster: &PublicKey, countersignatory: &PublicKey) -> ScriptBuf {
685         let broadcaster_funding_key = broadcaster.serialize();
686         let countersignatory_funding_key = countersignatory.serialize();
687
688         make_funding_redeemscript_from_slices(&broadcaster_funding_key, &countersignatory_funding_key)
689 }
690
691 pub(crate) fn make_funding_redeemscript_from_slices(broadcaster_funding_key: &[u8; 33], countersignatory_funding_key: &[u8; 33]) -> ScriptBuf {
692         let builder = Builder::new().push_opcode(opcodes::all::OP_PUSHNUM_2);
693         if broadcaster_funding_key[..] < countersignatory_funding_key[..] {
694                 builder.push_slice(broadcaster_funding_key)
695                         .push_slice(countersignatory_funding_key)
696         } else {
697                 builder.push_slice(countersignatory_funding_key)
698                         .push_slice(broadcaster_funding_key)
699         }.push_opcode(opcodes::all::OP_PUSHNUM_2).push_opcode(opcodes::all::OP_CHECKMULTISIG).into_script()
700 }
701
702 /// Builds an unsigned HTLC-Success or HTLC-Timeout transaction from the given channel and HTLC
703 /// parameters. This is used by [`TrustedCommitmentTransaction::get_htlc_sigs`] to fetch the
704 /// transaction which needs signing, and can be used to construct an HTLC transaction which is
705 /// broadcastable given a counterparty HTLC signature.
706 ///
707 /// Panics if htlc.transaction_output_index.is_none() (as such HTLCs do not appear in the
708 /// commitment transaction).
709 pub fn build_htlc_transaction(commitment_txid: &Txid, feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey) -> Transaction {
710         let mut txins: Vec<TxIn> = Vec::new();
711         txins.push(build_htlc_input(commitment_txid, htlc, channel_type_features));
712
713         let mut txouts: Vec<TxOut> = Vec::new();
714         txouts.push(build_htlc_output(
715                 feerate_per_kw, contest_delay, htlc, channel_type_features,
716                 broadcaster_delayed_payment_key, revocation_key
717         ));
718
719         Transaction {
720                 version: 2,
721                 lock_time: LockTime::from_consensus(if htlc.offered { htlc.cltv_expiry } else { 0 }),
722                 input: txins,
723                 output: txouts,
724         }
725 }
726
727 pub(crate) fn build_htlc_input(commitment_txid: &Txid, htlc: &HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures) -> TxIn {
728         TxIn {
729                 previous_output: OutPoint {
730                         txid: commitment_txid.clone(),
731                         vout: htlc.transaction_output_index.expect("Can't build an HTLC transaction for a dust output"),
732                 },
733                 script_sig: ScriptBuf::new(),
734                 sequence: Sequence(if channel_type_features.supports_anchors_zero_fee_htlc_tx() { 1 } else { 0 }),
735                 witness: Witness::new(),
736         }
737 }
738
739 pub(crate) fn build_htlc_output(
740         feerate_per_kw: u32, contest_delay: u16, htlc: &HTLCOutputInCommitment, channel_type_features: &ChannelTypeFeatures, broadcaster_delayed_payment_key: &PublicKey, revocation_key: &PublicKey
741 ) -> TxOut {
742         let weight = if htlc.offered {
743                 htlc_timeout_tx_weight(channel_type_features)
744         } else {
745                 htlc_success_tx_weight(channel_type_features)
746         };
747         let output_value = if channel_type_features.supports_anchors_zero_fee_htlc_tx() && !channel_type_features.supports_anchors_nonzero_fee_htlc_tx() {
748                 htlc.amount_msat / 1000
749         } else {
750                 let total_fee = feerate_per_kw as u64 * weight / 1000;
751                 htlc.amount_msat / 1000 - total_fee
752         };
753
754         TxOut {
755                 script_pubkey: get_revokeable_redeemscript(revocation_key, contest_delay, broadcaster_delayed_payment_key).to_v0_p2wsh(),
756                 value: output_value,
757         }
758 }
759
760 /// Returns the witness required to satisfy and spend a HTLC input.
761 pub fn build_htlc_input_witness(
762         local_sig: &Signature, remote_sig: &Signature, preimage: &Option<PaymentPreimage>,
763         redeem_script: &Script, channel_type_features: &ChannelTypeFeatures,
764 ) -> Witness {
765         let remote_sighash_type = if channel_type_features.supports_anchors_zero_fee_htlc_tx() {
766                 EcdsaSighashType::SinglePlusAnyoneCanPay
767         } else {
768                 EcdsaSighashType::All
769         };
770
771         let mut witness = Witness::new();
772         // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
773         witness.push(vec![]);
774         witness.push_bitcoin_signature(&remote_sig.serialize_der(), remote_sighash_type);
775         witness.push_bitcoin_signature(&local_sig.serialize_der(), EcdsaSighashType::All);
776         if let Some(preimage) = preimage {
777                 witness.push(preimage.0.to_vec());
778         } else {
779                 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
780                 witness.push(vec![]);
781         }
782         witness.push(redeem_script.to_bytes());
783         witness
784 }
785
786 /// Pre-anchors channel type features did not use to get serialized in the following six structs:
787 /// â€” [`ChannelTransactionParameters`]
788 /// â€” [`CommitmentTransaction`]
789 /// â€” [`CounterpartyOfferedHTLCOutput`]
790 /// â€” [`CounterpartyReceivedHTLCOutput`]
791 /// â€” [`HolderHTLCOutput`]
792 /// â€” [`HolderFundingOutput`]
793 ///
794 /// To ensure a forwards-compatible serialization, we use odd TLV fields. However, if new features
795 /// are used that could break security, where old signers should be prevented from handling the
796 /// serialized data, an optional even-field TLV will be used as a stand-in to break compatibility.
797 ///
798 /// This method determines whether or not that option needs to be set based on the chanenl type
799 /// features, and returns it.
800 ///
801 /// [`CounterpartyOfferedHTLCOutput`]: crate::chain::package::CounterpartyOfferedHTLCOutput
802 /// [`CounterpartyReceivedHTLCOutput`]: crate::chain::package::CounterpartyReceivedHTLCOutput
803 /// [`HolderHTLCOutput`]: crate::chain::package::HolderHTLCOutput
804 /// [`HolderFundingOutput`]: crate::chain::package::HolderFundingOutput
805 pub(crate) fn legacy_deserialization_prevention_marker_for_channel_type_features(features: &ChannelTypeFeatures) -> Option<()> {
806         let mut legacy_version_bit_set = ChannelTypeFeatures::only_static_remote_key();
807         legacy_version_bit_set.set_scid_privacy_required();
808         legacy_version_bit_set.set_zero_conf_required();
809
810         if features.is_subset(&legacy_version_bit_set) {
811                 None
812         } else {
813                 Some(())
814         }
815 }
816
817 /// Gets the witnessScript for the to_remote output when anchors are enabled.
818 #[inline]
819 pub fn get_to_countersignatory_with_anchors_redeemscript(payment_point: &PublicKey) -> ScriptBuf {
820         Builder::new()
821                 .push_slice(payment_point.serialize())
822                 .push_opcode(opcodes::all::OP_CHECKSIGVERIFY)
823                 .push_int(1)
824                 .push_opcode(opcodes::all::OP_CSV)
825                 .into_script()
826 }
827
828 /// Gets the witnessScript for an anchor output from the funding public key.
829 /// The witness in the spending input must be:
830 /// <BIP 143 funding_signature>
831 /// After 16 blocks of confirmation, an alternative satisfying witness could be:
832 /// <>
833 /// (empty vector required to satisfy compliance with MINIMALIF-standard rule)
834 #[inline]
835 pub fn get_anchor_redeemscript(funding_pubkey: &PublicKey) -> ScriptBuf {
836         Builder::new().push_slice(funding_pubkey.serialize())
837                 .push_opcode(opcodes::all::OP_CHECKSIG)
838                 .push_opcode(opcodes::all::OP_IFDUP)
839                 .push_opcode(opcodes::all::OP_NOTIF)
840                 .push_int(16)
841                 .push_opcode(opcodes::all::OP_CSV)
842                 .push_opcode(opcodes::all::OP_ENDIF)
843                 .into_script()
844 }
845
846 /// Locates the output with an anchor script paying to `funding_pubkey` within `commitment_tx`.
847 pub(crate) fn get_anchor_output<'a>(commitment_tx: &'a Transaction, funding_pubkey: &PublicKey) -> Option<(u32, &'a TxOut)> {
848         let anchor_script = chan_utils::get_anchor_redeemscript(funding_pubkey).to_v0_p2wsh();
849         commitment_tx.output.iter().enumerate()
850                 .find(|(_, txout)| txout.script_pubkey == anchor_script)
851                 .map(|(idx, txout)| (idx as u32, txout))
852 }
853
854 /// Returns the witness required to satisfy and spend an anchor input.
855 pub fn build_anchor_input_witness(funding_key: &PublicKey, funding_sig: &Signature) -> Witness {
856         let anchor_redeem_script = chan_utils::get_anchor_redeemscript(funding_key);
857         let mut ret = Witness::new();
858         ret.push_bitcoin_signature(&funding_sig.serialize_der(), EcdsaSighashType::All);
859         ret.push(anchor_redeem_script.as_bytes());
860         ret
861 }
862
863 /// Per-channel data used to build transactions in conjunction with the per-commitment data (CommitmentTransaction).
864 /// The fields are organized by holder/counterparty.
865 ///
866 /// Normally, this is converted to the broadcaster/countersignatory-organized DirectedChannelTransactionParameters
867 /// before use, via the as_holder_broadcastable and as_counterparty_broadcastable functions.
868 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
869 pub struct ChannelTransactionParameters {
870         /// Holder public keys
871         pub holder_pubkeys: ChannelPublicKeys,
872         /// The contest delay selected by the holder, which applies to counterparty-broadcast transactions
873         pub holder_selected_contest_delay: u16,
874         /// Whether the holder is the initiator of this channel.
875         /// This is an input to the commitment number obscure factor computation.
876         pub is_outbound_from_holder: bool,
877         /// The late-bound counterparty channel transaction parameters.
878         /// These parameters are populated at the point in the protocol where the counterparty provides them.
879         pub counterparty_parameters: Option<CounterpartyChannelTransactionParameters>,
880         /// The late-bound funding outpoint
881         pub funding_outpoint: Option<chain::transaction::OutPoint>,
882         /// This channel's type, as negotiated during channel open. For old objects where this field
883         /// wasn't serialized, it will default to static_remote_key at deserialization.
884         pub channel_type_features: ChannelTypeFeatures
885 }
886
887 /// Late-bound per-channel counterparty data used to build transactions.
888 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
889 pub struct CounterpartyChannelTransactionParameters {
890         /// Counter-party public keys
891         pub pubkeys: ChannelPublicKeys,
892         /// The contest delay selected by the counterparty, which applies to holder-broadcast transactions
893         pub selected_contest_delay: u16,
894 }
895
896 impl ChannelTransactionParameters {
897         /// Whether the late bound parameters are populated.
898         pub fn is_populated(&self) -> bool {
899                 self.counterparty_parameters.is_some() && self.funding_outpoint.is_some()
900         }
901
902         /// Convert the holder/counterparty parameters to broadcaster/countersignatory-organized parameters,
903         /// given that the holder is the broadcaster.
904         ///
905         /// self.is_populated() must be true before calling this function.
906         pub fn as_holder_broadcastable(&self) -> DirectedChannelTransactionParameters {
907                 assert!(self.is_populated(), "self.late_parameters must be set before using as_holder_broadcastable");
908                 DirectedChannelTransactionParameters {
909                         inner: self,
910                         holder_is_broadcaster: true
911                 }
912         }
913
914         /// Convert the holder/counterparty parameters to broadcaster/countersignatory-organized parameters,
915         /// given that the counterparty is the broadcaster.
916         ///
917         /// self.is_populated() must be true before calling this function.
918         pub fn as_counterparty_broadcastable(&self) -> DirectedChannelTransactionParameters {
919                 assert!(self.is_populated(), "self.late_parameters must be set before using as_counterparty_broadcastable");
920                 DirectedChannelTransactionParameters {
921                         inner: self,
922                         holder_is_broadcaster: false
923                 }
924         }
925 }
926
927 impl_writeable_tlv_based!(CounterpartyChannelTransactionParameters, {
928         (0, pubkeys, required),
929         (2, selected_contest_delay, required),
930 });
931
932 impl Writeable for ChannelTransactionParameters {
933         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
934                 let legacy_deserialization_prevention_marker = legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
935                 write_tlv_fields!(writer, {
936                         (0, self.holder_pubkeys, required),
937                         (2, self.holder_selected_contest_delay, required),
938                         (4, self.is_outbound_from_holder, required),
939                         (6, self.counterparty_parameters, option),
940                         (8, self.funding_outpoint, option),
941                         (10, legacy_deserialization_prevention_marker, option),
942                         (11, self.channel_type_features, required),
943                 });
944                 Ok(())
945         }
946 }
947
948 impl Readable for ChannelTransactionParameters {
949         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
950                 let mut holder_pubkeys = RequiredWrapper(None);
951                 let mut holder_selected_contest_delay = RequiredWrapper(None);
952                 let mut is_outbound_from_holder = RequiredWrapper(None);
953                 let mut counterparty_parameters = None;
954                 let mut funding_outpoint = None;
955                 let mut _legacy_deserialization_prevention_marker: Option<()> = None;
956                 let mut channel_type_features = None;
957
958                 read_tlv_fields!(reader, {
959                         (0, holder_pubkeys, required),
960                         (2, holder_selected_contest_delay, required),
961                         (4, is_outbound_from_holder, required),
962                         (6, counterparty_parameters, option),
963                         (8, funding_outpoint, option),
964                         (10, _legacy_deserialization_prevention_marker, option),
965                         (11, channel_type_features, option),
966                 });
967
968                 let mut additional_features = ChannelTypeFeatures::empty();
969                 additional_features.set_anchors_nonzero_fee_htlc_tx_required();
970                 chain::package::verify_channel_type_features(&channel_type_features, Some(&additional_features))?;
971
972                 Ok(Self {
973                         holder_pubkeys: holder_pubkeys.0.unwrap(),
974                         holder_selected_contest_delay: holder_selected_contest_delay.0.unwrap(),
975                         is_outbound_from_holder: is_outbound_from_holder.0.unwrap(),
976                         counterparty_parameters,
977                         funding_outpoint,
978                         channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
979                 })
980         }
981 }
982
983 /// Static channel fields used to build transactions given per-commitment fields, organized by
984 /// broadcaster/countersignatory.
985 ///
986 /// This is derived from the holder/counterparty-organized ChannelTransactionParameters via the
987 /// as_holder_broadcastable and as_counterparty_broadcastable functions.
988 pub struct DirectedChannelTransactionParameters<'a> {
989         /// The holder's channel static parameters
990         inner: &'a ChannelTransactionParameters,
991         /// Whether the holder is the broadcaster
992         holder_is_broadcaster: bool,
993 }
994
995 impl<'a> DirectedChannelTransactionParameters<'a> {
996         /// Get the channel pubkeys for the broadcaster
997         pub fn broadcaster_pubkeys(&self) -> &'a ChannelPublicKeys {
998                 if self.holder_is_broadcaster {
999                         &self.inner.holder_pubkeys
1000                 } else {
1001                         &self.inner.counterparty_parameters.as_ref().unwrap().pubkeys
1002                 }
1003         }
1004
1005         /// Get the channel pubkeys for the countersignatory
1006         pub fn countersignatory_pubkeys(&self) -> &'a ChannelPublicKeys {
1007                 if self.holder_is_broadcaster {
1008                         &self.inner.counterparty_parameters.as_ref().unwrap().pubkeys
1009                 } else {
1010                         &self.inner.holder_pubkeys
1011                 }
1012         }
1013
1014         /// Get the contest delay applicable to the transactions.
1015         /// Note that the contest delay was selected by the countersignatory.
1016         pub fn contest_delay(&self) -> u16 {
1017                 let counterparty_parameters = self.inner.counterparty_parameters.as_ref().unwrap();
1018                 if self.holder_is_broadcaster { counterparty_parameters.selected_contest_delay } else { self.inner.holder_selected_contest_delay }
1019         }
1020
1021         /// Whether the channel is outbound from the broadcaster.
1022         ///
1023         /// The boolean representing the side that initiated the channel is
1024         /// an input to the commitment number obscure factor computation.
1025         pub fn is_outbound(&self) -> bool {
1026                 if self.holder_is_broadcaster { self.inner.is_outbound_from_holder } else { !self.inner.is_outbound_from_holder }
1027         }
1028
1029         /// The funding outpoint
1030         pub fn funding_outpoint(&self) -> OutPoint {
1031                 self.inner.funding_outpoint.unwrap().into_bitcoin_outpoint()
1032         }
1033
1034         /// Whether to use anchors for this channel
1035         pub fn channel_type_features(&self) -> &'a ChannelTypeFeatures {
1036                 &self.inner.channel_type_features
1037         }
1038 }
1039
1040 /// Information needed to build and sign a holder's commitment transaction.
1041 ///
1042 /// The transaction is only signed once we are ready to broadcast.
1043 #[derive(Clone, Debug)]
1044 pub struct HolderCommitmentTransaction {
1045         inner: CommitmentTransaction,
1046         /// Our counterparty's signature for the transaction
1047         pub counterparty_sig: Signature,
1048         /// All non-dust counterparty HTLC signatures, in the order they appear in the transaction
1049         pub counterparty_htlc_sigs: Vec<Signature>,
1050         // Which order the signatures should go in when constructing the final commitment tx witness.
1051         // The user should be able to reconstruct this themselves, so we don't bother to expose it.
1052         holder_sig_first: bool,
1053 }
1054
1055 impl Deref for HolderCommitmentTransaction {
1056         type Target = CommitmentTransaction;
1057
1058         fn deref(&self) -> &Self::Target { &self.inner }
1059 }
1060
1061 impl Eq for HolderCommitmentTransaction {}
1062 impl PartialEq for HolderCommitmentTransaction {
1063         // We dont care whether we are signed in equality comparison
1064         fn eq(&self, o: &Self) -> bool {
1065                 self.inner == o.inner
1066         }
1067 }
1068
1069 impl_writeable_tlv_based!(HolderCommitmentTransaction, {
1070         (0, inner, required),
1071         (2, counterparty_sig, required),
1072         (4, holder_sig_first, required),
1073         (6, counterparty_htlc_sigs, required_vec),
1074 });
1075
1076 impl HolderCommitmentTransaction {
1077         #[cfg(test)]
1078         pub fn dummy(htlcs: &mut Vec<(HTLCOutputInCommitment, ())>) -> Self {
1079                 let secp_ctx = Secp256k1::new();
1080                 let dummy_key = PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1081                 let dummy_sig = sign(&secp_ctx, &secp256k1::Message::from_slice(&[42; 32]).unwrap(), &SecretKey::from_slice(&[42; 32]).unwrap());
1082
1083                 let keys = TxCreationKeys {
1084                         per_commitment_point: dummy_key.clone(),
1085                         revocation_key: dummy_key.clone(),
1086                         broadcaster_htlc_key: dummy_key.clone(),
1087                         countersignatory_htlc_key: dummy_key.clone(),
1088                         broadcaster_delayed_payment_key: dummy_key.clone(),
1089                 };
1090                 let channel_pubkeys = ChannelPublicKeys {
1091                         funding_pubkey: dummy_key.clone(),
1092                         revocation_basepoint: dummy_key.clone(),
1093                         payment_point: dummy_key.clone(),
1094                         delayed_payment_basepoint: dummy_key.clone(),
1095                         htlc_basepoint: dummy_key.clone()
1096                 };
1097                 let channel_parameters = ChannelTransactionParameters {
1098                         holder_pubkeys: channel_pubkeys.clone(),
1099                         holder_selected_contest_delay: 0,
1100                         is_outbound_from_holder: false,
1101                         counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: channel_pubkeys.clone(), selected_contest_delay: 0 }),
1102                         funding_outpoint: Some(chain::transaction::OutPoint { txid: Txid::all_zeros(), index: 0 }),
1103                         channel_type_features: ChannelTypeFeatures::only_static_remote_key(),
1104                 };
1105                 let mut counterparty_htlc_sigs = Vec::new();
1106                 for _ in 0..htlcs.len() {
1107                         counterparty_htlc_sigs.push(dummy_sig);
1108                 }
1109                 let inner = CommitmentTransaction::new_with_auxiliary_htlc_data(0, 0, 0, dummy_key.clone(), dummy_key.clone(), keys, 0, htlcs, &channel_parameters.as_counterparty_broadcastable());
1110                 htlcs.sort_by_key(|htlc| htlc.0.transaction_output_index);
1111                 HolderCommitmentTransaction {
1112                         inner,
1113                         counterparty_sig: dummy_sig,
1114                         counterparty_htlc_sigs,
1115                         holder_sig_first: false
1116                 }
1117         }
1118
1119         /// Create a new holder transaction with the given counterparty signatures.
1120         /// The funding keys are used to figure out which signature should go first when building the transaction for broadcast.
1121         pub fn new(commitment_tx: CommitmentTransaction, counterparty_sig: Signature, counterparty_htlc_sigs: Vec<Signature>, holder_funding_key: &PublicKey, counterparty_funding_key: &PublicKey) -> Self {
1122                 Self {
1123                         inner: commitment_tx,
1124                         counterparty_sig,
1125                         counterparty_htlc_sigs,
1126                         holder_sig_first: holder_funding_key.serialize()[..] < counterparty_funding_key.serialize()[..],
1127                 }
1128         }
1129
1130         pub(crate) fn add_holder_sig(&self, funding_redeemscript: &Script, holder_sig: Signature) -> Transaction {
1131                 // First push the multisig dummy, note that due to BIP147 (NULLDUMMY) it must be a zero-length element.
1132                 let mut tx = self.inner.built.transaction.clone();
1133                 tx.input[0].witness.push(Vec::new());
1134
1135                 if self.holder_sig_first {
1136                         tx.input[0].witness.push_bitcoin_signature(&holder_sig.serialize_der(), EcdsaSighashType::All);
1137                         tx.input[0].witness.push_bitcoin_signature(&self.counterparty_sig.serialize_der(), EcdsaSighashType::All);
1138                 } else {
1139                         tx.input[0].witness.push_bitcoin_signature(&self.counterparty_sig.serialize_der(), EcdsaSighashType::All);
1140                         tx.input[0].witness.push_bitcoin_signature(&holder_sig.serialize_der(), EcdsaSighashType::All);
1141                 }
1142
1143                 tx.input[0].witness.push(funding_redeemscript.as_bytes().to_vec());
1144                 tx
1145         }
1146 }
1147
1148 /// A pre-built Bitcoin commitment transaction and its txid.
1149 #[derive(Clone, Debug)]
1150 pub struct BuiltCommitmentTransaction {
1151         /// The commitment transaction
1152         pub transaction: Transaction,
1153         /// The txid for the commitment transaction.
1154         ///
1155         /// This is provided as a performance optimization, instead of calling transaction.txid()
1156         /// multiple times.
1157         pub txid: Txid,
1158 }
1159
1160 impl_writeable_tlv_based!(BuiltCommitmentTransaction, {
1161         (0, transaction, required),
1162         (2, txid, required),
1163 });
1164
1165 impl BuiltCommitmentTransaction {
1166         /// Get the SIGHASH_ALL sighash value of the transaction.
1167         ///
1168         /// This can be used to verify a signature.
1169         pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message {
1170                 let sighash = &sighash::SighashCache::new(&self.transaction).segwit_signature_hash(0, funding_redeemscript, channel_value_satoshis, EcdsaSighashType::All).unwrap()[..];
1171                 hash_to_message!(sighash)
1172         }
1173
1174         /// Signs the counterparty's commitment transaction.
1175         pub fn sign_counterparty_commitment<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
1176                 let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
1177                 sign(secp_ctx, &sighash, funding_key)
1178         }
1179
1180         /// Signs the holder commitment transaction because we are about to broadcast it.
1181         pub fn sign_holder_commitment<T: secp256k1::Signing, ES: Deref>(
1182                 &self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64,
1183                 entropy_source: &ES, secp_ctx: &Secp256k1<T>
1184         ) -> Signature where ES::Target: EntropySource {
1185                 let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
1186                 sign_with_aux_rand(secp_ctx, &sighash, funding_key, entropy_source)
1187         }
1188 }
1189
1190 /// This class tracks the per-transaction information needed to build a closing transaction and will
1191 /// actually build it and sign.
1192 ///
1193 /// This class can be used inside a signer implementation to generate a signature given the relevant
1194 /// secret key.
1195 #[derive(Clone, Hash, PartialEq, Eq)]
1196 pub struct ClosingTransaction {
1197         to_holder_value_sat: u64,
1198         to_counterparty_value_sat: u64,
1199         to_holder_script: ScriptBuf,
1200         to_counterparty_script: ScriptBuf,
1201         built: Transaction,
1202 }
1203
1204 impl ClosingTransaction {
1205         /// Construct an object of the class
1206         pub fn new(
1207                 to_holder_value_sat: u64,
1208                 to_counterparty_value_sat: u64,
1209                 to_holder_script: ScriptBuf,
1210                 to_counterparty_script: ScriptBuf,
1211                 funding_outpoint: OutPoint,
1212         ) -> Self {
1213                 let built = build_closing_transaction(
1214                         to_holder_value_sat, to_counterparty_value_sat,
1215                         to_holder_script.clone(), to_counterparty_script.clone(),
1216                         funding_outpoint
1217                 );
1218                 ClosingTransaction {
1219                         to_holder_value_sat,
1220                         to_counterparty_value_sat,
1221                         to_holder_script,
1222                         to_counterparty_script,
1223                         built
1224                 }
1225         }
1226
1227         /// Trust our pre-built transaction.
1228         ///
1229         /// Applies a wrapper which allows access to the transaction.
1230         ///
1231         /// This should only be used if you fully trust the builder of this object. It should not
1232         /// be used by an external signer - instead use the verify function.
1233         pub fn trust(&self) -> TrustedClosingTransaction {
1234                 TrustedClosingTransaction { inner: self }
1235         }
1236
1237         /// Verify our pre-built transaction.
1238         ///
1239         /// Applies a wrapper which allows access to the transaction.
1240         ///
1241         /// An external validating signer must call this method before signing
1242         /// or using the built transaction.
1243         pub fn verify(&self, funding_outpoint: OutPoint) -> Result<TrustedClosingTransaction, ()> {
1244                 let built = build_closing_transaction(
1245                         self.to_holder_value_sat, self.to_counterparty_value_sat,
1246                         self.to_holder_script.clone(), self.to_counterparty_script.clone(),
1247                         funding_outpoint
1248                 );
1249                 if self.built != built {
1250                         return Err(())
1251                 }
1252                 Ok(TrustedClosingTransaction { inner: self })
1253         }
1254
1255         /// The value to be sent to the holder, or zero if the output will be omitted
1256         pub fn to_holder_value_sat(&self) -> u64 {
1257                 self.to_holder_value_sat
1258         }
1259
1260         /// The value to be sent to the counterparty, or zero if the output will be omitted
1261         pub fn to_counterparty_value_sat(&self) -> u64 {
1262                 self.to_counterparty_value_sat
1263         }
1264
1265         /// The destination of the holder's output
1266         pub fn to_holder_script(&self) -> &Script {
1267                 &self.to_holder_script
1268         }
1269
1270         /// The destination of the counterparty's output
1271         pub fn to_counterparty_script(&self) -> &Script {
1272                 &self.to_counterparty_script
1273         }
1274 }
1275
1276 /// A wrapper on ClosingTransaction indicating that the built bitcoin
1277 /// transaction is trusted.
1278 ///
1279 /// See trust() and verify() functions on CommitmentTransaction.
1280 ///
1281 /// This structure implements Deref.
1282 pub struct TrustedClosingTransaction<'a> {
1283         inner: &'a ClosingTransaction,
1284 }
1285
1286 impl<'a> Deref for TrustedClosingTransaction<'a> {
1287         type Target = ClosingTransaction;
1288
1289         fn deref(&self) -> &Self::Target { self.inner }
1290 }
1291
1292 impl<'a> TrustedClosingTransaction<'a> {
1293         /// The pre-built Bitcoin commitment transaction
1294         pub fn built_transaction(&self) -> &'a Transaction {
1295                 &self.inner.built
1296         }
1297
1298         /// Get the SIGHASH_ALL sighash value of the transaction.
1299         ///
1300         /// This can be used to verify a signature.
1301         pub fn get_sighash_all(&self, funding_redeemscript: &Script, channel_value_satoshis: u64) -> Message {
1302                 let sighash = &sighash::SighashCache::new(&self.inner.built).segwit_signature_hash(0, funding_redeemscript, channel_value_satoshis, EcdsaSighashType::All).unwrap()[..];
1303                 hash_to_message!(sighash)
1304         }
1305
1306         /// Sign a transaction, either because we are counter-signing the counterparty's transaction or
1307         /// because we are about to broadcast a holder transaction.
1308         pub fn sign<T: secp256k1::Signing>(&self, funding_key: &SecretKey, funding_redeemscript: &Script, channel_value_satoshis: u64, secp_ctx: &Secp256k1<T>) -> Signature {
1309                 let sighash = self.get_sighash_all(funding_redeemscript, channel_value_satoshis);
1310                 sign(secp_ctx, &sighash, funding_key)
1311         }
1312 }
1313
1314 /// This class tracks the per-transaction information needed to build a commitment transaction and will
1315 /// actually build it and sign.  It is used for holder transactions that we sign only when needed
1316 /// and for transactions we sign for the counterparty.
1317 ///
1318 /// This class can be used inside a signer implementation to generate a signature given the relevant
1319 /// secret key.
1320 #[derive(Clone, Debug)]
1321 pub struct CommitmentTransaction {
1322         commitment_number: u64,
1323         to_broadcaster_value_sat: u64,
1324         to_countersignatory_value_sat: u64,
1325         to_broadcaster_delay: Option<u16>, // Added in 0.0.117
1326         feerate_per_kw: u32,
1327         htlcs: Vec<HTLCOutputInCommitment>,
1328         // Note that on upgrades, some features of existing outputs may be missed.
1329         channel_type_features: ChannelTypeFeatures,
1330         // A cache of the parties' pubkeys required to construct the transaction, see doc for trust()
1331         keys: TxCreationKeys,
1332         // For access to the pre-built transaction, see doc for trust()
1333         built: BuiltCommitmentTransaction,
1334 }
1335
1336 impl Eq for CommitmentTransaction {}
1337 impl PartialEq for CommitmentTransaction {
1338         fn eq(&self, o: &Self) -> bool {
1339                 let eq = self.commitment_number == o.commitment_number &&
1340                         self.to_broadcaster_value_sat == o.to_broadcaster_value_sat &&
1341                         self.to_countersignatory_value_sat == o.to_countersignatory_value_sat &&
1342                         self.feerate_per_kw == o.feerate_per_kw &&
1343                         self.htlcs == o.htlcs &&
1344                         self.channel_type_features == o.channel_type_features &&
1345                         self.keys == o.keys;
1346                 if eq {
1347                         debug_assert_eq!(self.built.transaction, o.built.transaction);
1348                         debug_assert_eq!(self.built.txid, o.built.txid);
1349                 }
1350                 eq
1351         }
1352 }
1353
1354 impl Writeable for CommitmentTransaction {
1355         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1356                 let legacy_deserialization_prevention_marker = legacy_deserialization_prevention_marker_for_channel_type_features(&self.channel_type_features);
1357                 write_tlv_fields!(writer, {
1358                         (0, self.commitment_number, required),
1359                         (1, self.to_broadcaster_delay, option),
1360                         (2, self.to_broadcaster_value_sat, required),
1361                         (4, self.to_countersignatory_value_sat, required),
1362                         (6, self.feerate_per_kw, required),
1363                         (8, self.keys, required),
1364                         (10, self.built, required),
1365                         (12, self.htlcs, required_vec),
1366                         (14, legacy_deserialization_prevention_marker, option),
1367                         (15, self.channel_type_features, required),
1368                 });
1369                 Ok(())
1370         }
1371 }
1372
1373 impl Readable for CommitmentTransaction {
1374         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
1375                 _init_and_read_len_prefixed_tlv_fields!(reader, {
1376                         (0, commitment_number, required),
1377                         (1, to_broadcaster_delay, option),
1378                         (2, to_broadcaster_value_sat, required),
1379                         (4, to_countersignatory_value_sat, required),
1380                         (6, feerate_per_kw, required),
1381                         (8, keys, required),
1382                         (10, built, required),
1383                         (12, htlcs, required_vec),
1384                         (14, _legacy_deserialization_prevention_marker, option),
1385                         (15, channel_type_features, option),
1386                 });
1387
1388                 let mut additional_features = ChannelTypeFeatures::empty();
1389                 additional_features.set_anchors_nonzero_fee_htlc_tx_required();
1390                 chain::package::verify_channel_type_features(&channel_type_features, Some(&additional_features))?;
1391
1392                 Ok(Self {
1393                         commitment_number: commitment_number.0.unwrap(),
1394                         to_broadcaster_value_sat: to_broadcaster_value_sat.0.unwrap(),
1395                         to_countersignatory_value_sat: to_countersignatory_value_sat.0.unwrap(),
1396                         to_broadcaster_delay,
1397                         feerate_per_kw: feerate_per_kw.0.unwrap(),
1398                         keys: keys.0.unwrap(),
1399                         built: built.0.unwrap(),
1400                         htlcs,
1401                         channel_type_features: channel_type_features.unwrap_or(ChannelTypeFeatures::only_static_remote_key())
1402                 })
1403         }
1404 }
1405
1406 impl CommitmentTransaction {
1407         /// Construct an object of the class while assigning transaction output indices to HTLCs.
1408         ///
1409         /// Populates HTLCOutputInCommitment.transaction_output_index in htlcs_with_aux.
1410         ///
1411         /// The generic T allows the caller to match the HTLC output index with auxiliary data.
1412         /// This auxiliary data is not stored in this object.
1413         ///
1414         /// Only include HTLCs that are above the dust limit for the channel.
1415         ///
1416         /// This is not exported to bindings users due to the generic though we likely should expose a version without
1417         pub fn new_with_auxiliary_htlc_data<T>(commitment_number: u64, to_broadcaster_value_sat: u64, to_countersignatory_value_sat: u64, broadcaster_funding_key: PublicKey, countersignatory_funding_key: PublicKey, keys: TxCreationKeys, feerate_per_kw: u32, htlcs_with_aux: &mut Vec<(HTLCOutputInCommitment, T)>, channel_parameters: &DirectedChannelTransactionParameters) -> CommitmentTransaction {
1418                 // Sort outputs and populate output indices while keeping track of the auxiliary data
1419                 let (outputs, htlcs) = Self::internal_build_outputs(&keys, to_broadcaster_value_sat, to_countersignatory_value_sat, htlcs_with_aux, channel_parameters, &broadcaster_funding_key, &countersignatory_funding_key).unwrap();
1420
1421                 let (obscured_commitment_transaction_number, txins) = Self::internal_build_inputs(commitment_number, channel_parameters);
1422                 let transaction = Self::make_transaction(obscured_commitment_transaction_number, txins, outputs);
1423                 let txid = transaction.txid();
1424                 CommitmentTransaction {
1425                         commitment_number,
1426                         to_broadcaster_value_sat,
1427                         to_countersignatory_value_sat,
1428                         to_broadcaster_delay: Some(channel_parameters.contest_delay()),
1429                         feerate_per_kw,
1430                         htlcs,
1431                         channel_type_features: channel_parameters.channel_type_features().clone(),
1432                         keys,
1433                         built: BuiltCommitmentTransaction {
1434                                 transaction,
1435                                 txid
1436                         },
1437                 }
1438         }
1439
1440         /// Use non-zero fee anchors
1441         ///
1442         /// This is not exported to bindings users due to move, and also not likely to be useful for binding users
1443         pub fn with_non_zero_fee_anchors(mut self) -> Self {
1444                 self.channel_type_features.set_anchors_nonzero_fee_htlc_tx_required();
1445                 self
1446         }
1447
1448         fn internal_rebuild_transaction(&self, keys: &TxCreationKeys, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_funding_key: &PublicKey, countersignatory_funding_key: &PublicKey) -> Result<BuiltCommitmentTransaction, ()> {
1449                 let (obscured_commitment_transaction_number, txins) = Self::internal_build_inputs(self.commitment_number, channel_parameters);
1450
1451                 let mut htlcs_with_aux = self.htlcs.iter().map(|h| (h.clone(), ())).collect();
1452                 let (outputs, _) = Self::internal_build_outputs(keys, self.to_broadcaster_value_sat, self.to_countersignatory_value_sat, &mut htlcs_with_aux, channel_parameters, broadcaster_funding_key, countersignatory_funding_key)?;
1453
1454                 let transaction = Self::make_transaction(obscured_commitment_transaction_number, txins, outputs);
1455                 let txid = transaction.txid();
1456                 let built_transaction = BuiltCommitmentTransaction {
1457                         transaction,
1458                         txid
1459                 };
1460                 Ok(built_transaction)
1461         }
1462
1463         fn make_transaction(obscured_commitment_transaction_number: u64, txins: Vec<TxIn>, outputs: Vec<TxOut>) -> Transaction {
1464                 Transaction {
1465                         version: 2,
1466                         lock_time: LockTime::from_consensus(((0x20 as u32) << 8 * 3) | ((obscured_commitment_transaction_number & 0xffffffu64) as u32)),
1467                         input: txins,
1468                         output: outputs,
1469                 }
1470         }
1471
1472         // This is used in two cases:
1473         // - initial sorting of outputs / HTLCs in the constructor, in which case T is auxiliary data the
1474         //   caller needs to have sorted together with the HTLCs so it can keep track of the output index
1475         // - building of a bitcoin transaction during a verify() call, in which case T is just ()
1476         fn internal_build_outputs<T>(keys: &TxCreationKeys, to_broadcaster_value_sat: u64, to_countersignatory_value_sat: u64, htlcs_with_aux: &mut Vec<(HTLCOutputInCommitment, T)>, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_funding_key: &PublicKey, countersignatory_funding_key: &PublicKey) -> Result<(Vec<TxOut>, Vec<HTLCOutputInCommitment>), ()> {
1477                 let countersignatory_pubkeys = channel_parameters.countersignatory_pubkeys();
1478                 let contest_delay = channel_parameters.contest_delay();
1479
1480                 let mut txouts: Vec<(TxOut, Option<&mut HTLCOutputInCommitment>)> = Vec::new();
1481
1482                 if to_countersignatory_value_sat > 0 {
1483                         let script = if channel_parameters.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
1484                             get_to_countersignatory_with_anchors_redeemscript(&countersignatory_pubkeys.payment_point).to_v0_p2wsh()
1485                         } else {
1486                             Payload::p2wpkh(&BitcoinPublicKey::new(countersignatory_pubkeys.payment_point)).unwrap().script_pubkey()
1487                         };
1488                         txouts.push((
1489                                 TxOut {
1490                                         script_pubkey: script.clone(),
1491                                         value: to_countersignatory_value_sat,
1492                                 },
1493                                 None,
1494                         ))
1495                 }
1496
1497                 if to_broadcaster_value_sat > 0 {
1498                         let redeem_script = get_revokeable_redeemscript(
1499                                 &keys.revocation_key,
1500                                 contest_delay,
1501                                 &keys.broadcaster_delayed_payment_key,
1502                         );
1503                         txouts.push((
1504                                 TxOut {
1505                                         script_pubkey: redeem_script.to_v0_p2wsh(),
1506                                         value: to_broadcaster_value_sat,
1507                                 },
1508                                 None,
1509                         ));
1510                 }
1511
1512                 if channel_parameters.channel_type_features().supports_anchors_zero_fee_htlc_tx() {
1513                         if to_broadcaster_value_sat > 0 || !htlcs_with_aux.is_empty() {
1514                                 let anchor_script = get_anchor_redeemscript(broadcaster_funding_key);
1515                                 txouts.push((
1516                                         TxOut {
1517                                                 script_pubkey: anchor_script.to_v0_p2wsh(),
1518                                                 value: ANCHOR_OUTPUT_VALUE_SATOSHI,
1519                                         },
1520                                         None,
1521                                 ));
1522                         }
1523
1524                         if to_countersignatory_value_sat > 0 || !htlcs_with_aux.is_empty() {
1525                                 let anchor_script = get_anchor_redeemscript(countersignatory_funding_key);
1526                                 txouts.push((
1527                                         TxOut {
1528                                                 script_pubkey: anchor_script.to_v0_p2wsh(),
1529                                                 value: ANCHOR_OUTPUT_VALUE_SATOSHI,
1530                                         },
1531                                         None,
1532                                 ));
1533                         }
1534                 }
1535
1536                 let mut htlcs = Vec::with_capacity(htlcs_with_aux.len());
1537                 for (htlc, _) in htlcs_with_aux {
1538                         let script = chan_utils::get_htlc_redeemscript(&htlc, &channel_parameters.channel_type_features(), &keys);
1539                         let txout = TxOut {
1540                                 script_pubkey: script.to_v0_p2wsh(),
1541                                 value: htlc.amount_msat / 1000,
1542                         };
1543                         txouts.push((txout, Some(htlc)));
1544                 }
1545
1546                 // Sort output in BIP-69 order (amount, scriptPubkey).  Tie-breaks based on HTLC
1547                 // CLTV expiration height.
1548                 sort_outputs(&mut txouts, |a, b| {
1549                         if let &Some(ref a_htlcout) = a {
1550                                 if let &Some(ref b_htlcout) = b {
1551                                         a_htlcout.cltv_expiry.cmp(&b_htlcout.cltv_expiry)
1552                                                 // Note that due to hash collisions, we have to have a fallback comparison
1553                                                 // here for fuzzing mode (otherwise at least chanmon_fail_consistency
1554                                                 // may fail)!
1555                                                 .then(a_htlcout.payment_hash.0.cmp(&b_htlcout.payment_hash.0))
1556                                 // For non-HTLC outputs, if they're copying our SPK we don't really care if we
1557                                 // close the channel due to mismatches - they're doing something dumb:
1558                                 } else { cmp::Ordering::Equal }
1559                         } else { cmp::Ordering::Equal }
1560                 });
1561
1562                 let mut outputs = Vec::with_capacity(txouts.len());
1563                 for (idx, out) in txouts.drain(..).enumerate() {
1564                         if let Some(htlc) = out.1 {
1565                                 htlc.transaction_output_index = Some(idx as u32);
1566                                 htlcs.push(htlc.clone());
1567                         }
1568                         outputs.push(out.0);
1569                 }
1570                 Ok((outputs, htlcs))
1571         }
1572
1573         fn internal_build_inputs(commitment_number: u64, channel_parameters: &DirectedChannelTransactionParameters) -> (u64, Vec<TxIn>) {
1574                 let broadcaster_pubkeys = channel_parameters.broadcaster_pubkeys();
1575                 let countersignatory_pubkeys = channel_parameters.countersignatory_pubkeys();
1576                 let commitment_transaction_number_obscure_factor = get_commitment_transaction_number_obscure_factor(
1577                         &broadcaster_pubkeys.payment_point,
1578                         &countersignatory_pubkeys.payment_point,
1579                         channel_parameters.is_outbound(),
1580                 );
1581
1582                 let obscured_commitment_transaction_number =
1583                         commitment_transaction_number_obscure_factor ^ (INITIAL_COMMITMENT_NUMBER - commitment_number);
1584
1585                 let txins = {
1586                         let mut ins: Vec<TxIn> = Vec::new();
1587                         ins.push(TxIn {
1588                                 previous_output: channel_parameters.funding_outpoint(),
1589                                 script_sig: ScriptBuf::new(),
1590                                 sequence: Sequence(((0x80 as u32) << 8 * 3)
1591                                         | ((obscured_commitment_transaction_number >> 3 * 8) as u32)),
1592                                 witness: Witness::new(),
1593                         });
1594                         ins
1595                 };
1596                 (obscured_commitment_transaction_number, txins)
1597         }
1598
1599         /// The backwards-counting commitment number
1600         pub fn commitment_number(&self) -> u64 {
1601                 self.commitment_number
1602         }
1603
1604         /// The per commitment point used by the broadcaster.
1605         pub fn per_commitment_point(&self) -> PublicKey {
1606                 self.keys.per_commitment_point
1607         }
1608
1609         /// The value to be sent to the broadcaster
1610         pub fn to_broadcaster_value_sat(&self) -> u64 {
1611                 self.to_broadcaster_value_sat
1612         }
1613
1614         /// The value to be sent to the counterparty
1615         pub fn to_countersignatory_value_sat(&self) -> u64 {
1616                 self.to_countersignatory_value_sat
1617         }
1618
1619         /// The feerate paid per 1000-weight-unit in this commitment transaction.
1620         pub fn feerate_per_kw(&self) -> u32 {
1621                 self.feerate_per_kw
1622         }
1623
1624         /// The non-dust HTLCs (direction, amt, height expiration, hash, transaction output index)
1625         /// which were included in this commitment transaction in output order.
1626         /// The transaction index is always populated.
1627         ///
1628         /// This is not exported to bindings users as we cannot currently convert Vec references to/from C, though we should
1629         /// expose a less effecient version which creates a Vec of references in the future.
1630         pub fn htlcs(&self) -> &Vec<HTLCOutputInCommitment> {
1631                 &self.htlcs
1632         }
1633
1634         /// Trust our pre-built transaction and derived transaction creation public keys.
1635         ///
1636         /// Applies a wrapper which allows access to these fields.
1637         ///
1638         /// This should only be used if you fully trust the builder of this object.  It should not
1639         /// be used by an external signer - instead use the verify function.
1640         pub fn trust(&self) -> TrustedCommitmentTransaction {
1641                 TrustedCommitmentTransaction { inner: self }
1642         }
1643
1644         /// Verify our pre-built transaction and derived transaction creation public keys.
1645         ///
1646         /// Applies a wrapper which allows access to these fields.
1647         ///
1648         /// An external validating signer must call this method before signing
1649         /// or using the built transaction.
1650         pub fn verify<T: secp256k1::Signing + secp256k1::Verification>(&self, channel_parameters: &DirectedChannelTransactionParameters, broadcaster_keys: &ChannelPublicKeys, countersignatory_keys: &ChannelPublicKeys, secp_ctx: &Secp256k1<T>) -> Result<TrustedCommitmentTransaction, ()> {
1651                 // This is the only field of the key cache that we trust
1652                 let per_commitment_point = self.keys.per_commitment_point;
1653                 let keys = TxCreationKeys::from_channel_static_keys(&per_commitment_point, broadcaster_keys, countersignatory_keys, secp_ctx);
1654                 if keys != self.keys {
1655                         return Err(());
1656                 }
1657                 let tx = self.internal_rebuild_transaction(&keys, channel_parameters, &broadcaster_keys.funding_pubkey, &countersignatory_keys.funding_pubkey)?;
1658                 if self.built.transaction != tx.transaction || self.built.txid != tx.txid {
1659                         return Err(());
1660                 }
1661                 Ok(TrustedCommitmentTransaction { inner: self })
1662         }
1663 }
1664
1665 /// A wrapper on CommitmentTransaction indicating that the derived fields (the built bitcoin
1666 /// transaction and the transaction creation keys) are trusted.
1667 ///
1668 /// See trust() and verify() functions on CommitmentTransaction.
1669 ///
1670 /// This structure implements Deref.
1671 pub struct TrustedCommitmentTransaction<'a> {
1672         inner: &'a CommitmentTransaction,
1673 }
1674
1675 impl<'a> Deref for TrustedCommitmentTransaction<'a> {
1676         type Target = CommitmentTransaction;
1677
1678         fn deref(&self) -> &Self::Target { self.inner }
1679 }
1680
1681 impl<'a> TrustedCommitmentTransaction<'a> {
1682         /// The transaction ID of the built Bitcoin transaction
1683         pub fn txid(&self) -> Txid {
1684                 self.inner.built.txid
1685         }
1686
1687         /// The pre-built Bitcoin commitment transaction
1688         pub fn built_transaction(&self) -> &'a BuiltCommitmentTransaction {
1689                 &self.inner.built
1690         }
1691
1692         /// The pre-calculated transaction creation public keys.
1693         pub fn keys(&self) -> &'a TxCreationKeys {
1694                 &self.inner.keys
1695         }
1696
1697         /// Should anchors be used.
1698         pub fn channel_type_features(&self) -> &'a ChannelTypeFeatures {
1699                 &self.inner.channel_type_features
1700         }
1701
1702         /// Get a signature for each HTLC which was included in the commitment transaction (ie for
1703         /// which HTLCOutputInCommitment::transaction_output_index.is_some()).
1704         ///
1705         /// The returned Vec has one entry for each HTLC, and in the same order.
1706         ///
1707         /// This function is only valid in the holder commitment context, it always uses EcdsaSighashType::All.
1708         pub fn get_htlc_sigs<T: secp256k1::Signing, ES: Deref>(
1709                 &self, htlc_base_key: &SecretKey, channel_parameters: &DirectedChannelTransactionParameters,
1710                 entropy_source: &ES, secp_ctx: &Secp256k1<T>,
1711         ) -> Result<Vec<Signature>, ()> where ES::Target: EntropySource {
1712                 let inner = self.inner;
1713                 let keys = &inner.keys;
1714                 let txid = inner.built.txid;
1715                 let mut ret = Vec::with_capacity(inner.htlcs.len());
1716                 let holder_htlc_key = derive_private_key(secp_ctx, &inner.keys.per_commitment_point, htlc_base_key);
1717
1718                 for this_htlc in inner.htlcs.iter() {
1719                         assert!(this_htlc.transaction_output_index.is_some());
1720                         let htlc_tx = build_htlc_transaction(&txid, inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc, &self.channel_type_features, &keys.broadcaster_delayed_payment_key, &keys.revocation_key);
1721
1722                         let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(&this_htlc, &self.channel_type_features, &keys.broadcaster_htlc_key, &keys.countersignatory_htlc_key, &keys.revocation_key);
1723
1724                         let sighash = hash_to_message!(&sighash::SighashCache::new(&htlc_tx).segwit_signature_hash(0, &htlc_redeemscript, this_htlc.amount_msat / 1000, EcdsaSighashType::All).unwrap()[..]);
1725                         ret.push(sign_with_aux_rand(secp_ctx, &sighash, &holder_htlc_key, entropy_source));
1726                 }
1727                 Ok(ret)
1728         }
1729
1730         /// Builds the second-level holder HTLC transaction for the HTLC with index `htlc_index`.
1731         pub(crate) fn build_unsigned_htlc_tx(
1732                 &self, channel_parameters: &DirectedChannelTransactionParameters, htlc_index: usize,
1733                 preimage: &Option<PaymentPreimage>,
1734         ) -> Transaction {
1735                 let keys = &self.inner.keys;
1736                 let this_htlc = &self.inner.htlcs[htlc_index];
1737                 assert!(this_htlc.transaction_output_index.is_some());
1738                 // if we don't have preimage for an HTLC-Success, we can't generate an HTLC transaction.
1739                 if !this_htlc.offered && preimage.is_none() { unreachable!(); }
1740                 // Further, we should never be provided the preimage for an HTLC-Timeout transaction.
1741                 if  this_htlc.offered && preimage.is_some() { unreachable!(); }
1742
1743                 build_htlc_transaction(
1744                         &self.inner.built.txid, self.inner.feerate_per_kw, channel_parameters.contest_delay(), &this_htlc,
1745                         &self.channel_type_features, &keys.broadcaster_delayed_payment_key, &keys.revocation_key
1746                 )
1747         }
1748
1749
1750         /// Builds the witness required to spend the input for the HTLC with index `htlc_index` in a
1751         /// second-level holder HTLC transaction.
1752         pub(crate) fn build_htlc_input_witness(
1753                 &self, htlc_index: usize, counterparty_signature: &Signature, signature: &Signature,
1754                 preimage: &Option<PaymentPreimage>
1755         ) -> Witness {
1756                 let keys = &self.inner.keys;
1757                 let htlc_redeemscript = get_htlc_redeemscript_with_explicit_keys(
1758                         &self.inner.htlcs[htlc_index], &self.channel_type_features, &keys.broadcaster_htlc_key,
1759                         &keys.countersignatory_htlc_key, &keys.revocation_key
1760                 );
1761                 chan_utils::build_htlc_input_witness(
1762                         signature, counterparty_signature, preimage, &htlc_redeemscript, &self.channel_type_features,
1763                 )
1764         }
1765
1766         /// Returns the index of the revokeable output, i.e. the `to_local` output sending funds to
1767         /// the broadcaster, in the built transaction, if any exists.
1768         ///
1769         /// There are two cases where this may return `None`:
1770         /// - The balance of the revokeable output is below the dust limit (only found on commitments
1771         /// early in the channel's lifetime, i.e. before the channel reserve is met).
1772         /// - This commitment was created before LDK 0.0.117. In this case, the
1773         /// commitment transaction previously didn't contain enough information to locate the
1774         /// revokeable output.
1775         pub fn revokeable_output_index(&self) -> Option<usize> {
1776                 let revokeable_redeemscript = get_revokeable_redeemscript(
1777                         &self.keys.revocation_key,
1778                         self.to_broadcaster_delay?,
1779                         &self.keys.broadcaster_delayed_payment_key,
1780                 );
1781                 let revokeable_p2wsh = revokeable_redeemscript.to_v0_p2wsh();
1782                 let outputs = &self.inner.built.transaction.output;
1783                 outputs.iter().enumerate()
1784                         .find(|(_, out)| out.script_pubkey == revokeable_p2wsh)
1785                         .map(|(idx, _)| idx)
1786         }
1787
1788         /// Helper method to build an unsigned justice transaction spending the revokeable
1789         /// `to_local` output to a destination script. Fee estimation accounts for the expected
1790         /// revocation witness data that will be added when signed.
1791         ///
1792         /// This method will error if the given fee rate results in a fee greater than the value
1793         /// of the output being spent, or if there exists no revokeable `to_local` output on this
1794         /// commitment transaction. See [`Self::revokeable_output_index`] for more details.
1795         ///
1796         /// The built transaction will allow fee bumping with RBF, and this method takes
1797         /// `feerate_per_kw` as an input such that multiple copies of a justice transaction at different
1798         /// fee rates may be built.
1799         pub fn build_to_local_justice_tx(&self, feerate_per_kw: u64, destination_script: ScriptBuf)
1800         -> Result<Transaction, ()> {
1801                 let output_idx = self.revokeable_output_index().ok_or(())?;
1802                 let input = vec![TxIn {
1803                         previous_output: OutPoint {
1804                                 txid: self.trust().txid(),
1805                                 vout: output_idx as u32,
1806                         },
1807                         script_sig: ScriptBuf::new(),
1808                         sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
1809                         witness: Witness::new(),
1810                 }];
1811                 let value = self.inner.built.transaction.output[output_idx].value;
1812                 let output = vec![TxOut {
1813                         script_pubkey: destination_script,
1814                         value,
1815                 }];
1816                 let mut justice_tx = Transaction {
1817                         version: 2,
1818                         lock_time: LockTime::ZERO,
1819                         input,
1820                         output,
1821                 };
1822                 let weight = justice_tx.weight().to_wu() + WEIGHT_REVOKED_OUTPUT;
1823                 let fee = fee_for_weight(feerate_per_kw as u32, weight);
1824                 justice_tx.output[0].value = value.checked_sub(fee).ok_or(())?;
1825                 Ok(justice_tx)
1826         }
1827
1828 }
1829
1830 /// Commitment transaction numbers which appear in the transactions themselves are XOR'd with a
1831 /// shared secret first. This prevents on-chain observers from discovering how many commitment
1832 /// transactions occurred in a channel before it was closed.
1833 ///
1834 /// This function gets the shared secret from relevant channel public keys and can be used to
1835 /// "decrypt" the commitment transaction number given a commitment transaction on-chain.
1836 pub fn get_commitment_transaction_number_obscure_factor(
1837         broadcaster_payment_basepoint: &PublicKey,
1838         countersignatory_payment_basepoint: &PublicKey,
1839         outbound_from_broadcaster: bool,
1840 ) -> u64 {
1841         let mut sha = Sha256::engine();
1842
1843         if outbound_from_broadcaster {
1844                 sha.input(&broadcaster_payment_basepoint.serialize());
1845                 sha.input(&countersignatory_payment_basepoint.serialize());
1846         } else {
1847                 sha.input(&countersignatory_payment_basepoint.serialize());
1848                 sha.input(&broadcaster_payment_basepoint.serialize());
1849         }
1850         let res = Sha256::from_engine(sha).to_byte_array();
1851
1852         ((res[26] as u64) << 5 * 8)
1853                 | ((res[27] as u64) << 4 * 8)
1854                 | ((res[28] as u64) << 3 * 8)
1855                 | ((res[29] as u64) << 2 * 8)
1856                 | ((res[30] as u64) << 1 * 8)
1857                 | ((res[31] as u64) << 0 * 8)
1858 }
1859
1860 #[cfg(test)]
1861 mod tests {
1862         use super::{CounterpartyCommitmentSecrets, ChannelPublicKeys};
1863         use crate::chain;
1864         use crate::prelude::*;
1865         use crate::ln::chan_utils::{get_htlc_redeemscript, get_to_countersignatory_with_anchors_redeemscript, CommitmentTransaction, TxCreationKeys, ChannelTransactionParameters, CounterpartyChannelTransactionParameters, HTLCOutputInCommitment};
1866         use bitcoin::secp256k1::{PublicKey, SecretKey, Secp256k1};
1867         use crate::util::test_utils;
1868         use crate::sign::{ChannelSigner, SignerProvider};
1869         use bitcoin::{Network, Txid, ScriptBuf};
1870         use bitcoin::hashes::Hash;
1871         use bitcoin::hashes::hex::FromHex;
1872         use crate::ln::PaymentHash;
1873         use bitcoin::address::Payload;
1874         use bitcoin::PublicKey as BitcoinPublicKey;
1875         use crate::ln::features::ChannelTypeFeatures;
1876
1877         struct TestCommitmentTxBuilder {
1878                 commitment_number: u64,
1879                 holder_funding_pubkey: PublicKey,
1880                 counterparty_funding_pubkey: PublicKey,
1881                 keys: TxCreationKeys,
1882                 feerate_per_kw: u32,
1883                 htlcs_with_aux: Vec<(HTLCOutputInCommitment, ())>,
1884                 channel_parameters: ChannelTransactionParameters,
1885                 counterparty_pubkeys: ChannelPublicKeys,
1886         }
1887
1888         impl TestCommitmentTxBuilder {
1889                 fn new() -> Self {
1890                         let secp_ctx = Secp256k1::new();
1891                         let seed = [42; 32];
1892                         let network = Network::Testnet;
1893                         let keys_provider = test_utils::TestKeysInterface::new(&seed, network);
1894                         let signer = keys_provider.derive_channel_signer(3000, keys_provider.generate_channel_keys_id(false, 1_000_000, 0));
1895                         let counterparty_signer = keys_provider.derive_channel_signer(3000, keys_provider.generate_channel_keys_id(true, 1_000_000, 1));
1896                         let delayed_payment_base = &signer.pubkeys().delayed_payment_basepoint;
1897                         let per_commitment_secret = SecretKey::from_slice(&<Vec<u8>>::from_hex("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100").unwrap()[..]).unwrap();
1898                         let per_commitment_point = PublicKey::from_secret_key(&secp_ctx, &per_commitment_secret);
1899                         let htlc_basepoint = &signer.pubkeys().htlc_basepoint;
1900                         let holder_pubkeys = signer.pubkeys();
1901                         let counterparty_pubkeys = counterparty_signer.pubkeys().clone();
1902                         let keys = TxCreationKeys::derive_new(&secp_ctx, &per_commitment_point, delayed_payment_base, htlc_basepoint, &counterparty_pubkeys.revocation_basepoint, &counterparty_pubkeys.htlc_basepoint);
1903                         let channel_parameters = ChannelTransactionParameters {
1904                                 holder_pubkeys: holder_pubkeys.clone(),
1905                                 holder_selected_contest_delay: 0,
1906                                 is_outbound_from_holder: false,
1907                                 counterparty_parameters: Some(CounterpartyChannelTransactionParameters { pubkeys: counterparty_pubkeys.clone(), selected_contest_delay: 0 }),
1908                                 funding_outpoint: Some(chain::transaction::OutPoint { txid: Txid::all_zeros(), index: 0 }),
1909                                 channel_type_features: ChannelTypeFeatures::only_static_remote_key(),
1910                         };
1911                         let htlcs_with_aux = Vec::new();
1912
1913                         Self {
1914                                 commitment_number: 0,
1915                                 holder_funding_pubkey: holder_pubkeys.funding_pubkey,
1916                                 counterparty_funding_pubkey: counterparty_pubkeys.funding_pubkey,
1917                                 keys,
1918                                 feerate_per_kw: 1,
1919                                 htlcs_with_aux,
1920                                 channel_parameters,
1921                                 counterparty_pubkeys,
1922                         }
1923                 }
1924
1925                 fn build(&mut self, to_broadcaster_sats: u64, to_countersignatory_sats: u64) -> CommitmentTransaction {
1926                         CommitmentTransaction::new_with_auxiliary_htlc_data(
1927                                 self.commitment_number, to_broadcaster_sats, to_countersignatory_sats,
1928                                 self.holder_funding_pubkey.clone(),
1929                                 self.counterparty_funding_pubkey.clone(),
1930                                 self.keys.clone(), self.feerate_per_kw,
1931                                 &mut self.htlcs_with_aux, &self.channel_parameters.as_holder_broadcastable()
1932                         )
1933                 }
1934         }
1935
1936         #[test]
1937         fn test_anchors() {
1938                 let mut builder = TestCommitmentTxBuilder::new();
1939
1940                 // Generate broadcaster and counterparty outputs
1941                 let tx = builder.build(1000, 2000);
1942                 assert_eq!(tx.built.transaction.output.len(), 2);
1943                 assert_eq!(tx.built.transaction.output[1].script_pubkey, Payload::p2wpkh(&BitcoinPublicKey::new(builder.counterparty_pubkeys.payment_point)).unwrap().script_pubkey());
1944
1945                 // Generate broadcaster and counterparty outputs as well as two anchors
1946                 builder.channel_parameters.channel_type_features = ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies();
1947                 let tx = builder.build(1000, 2000);
1948                 assert_eq!(tx.built.transaction.output.len(), 4);
1949                 assert_eq!(tx.built.transaction.output[3].script_pubkey, get_to_countersignatory_with_anchors_redeemscript(&builder.counterparty_pubkeys.payment_point).to_v0_p2wsh());
1950
1951                 // Generate broadcaster output and anchor
1952                 let tx = builder.build(3000, 0);
1953                 assert_eq!(tx.built.transaction.output.len(), 2);
1954
1955                 // Generate counterparty output and anchor
1956                 let tx = builder.build(0, 3000);
1957                 assert_eq!(tx.built.transaction.output.len(), 2);
1958
1959                 let received_htlc = HTLCOutputInCommitment {
1960                         offered: false,
1961                         amount_msat: 400000,
1962                         cltv_expiry: 100,
1963                         payment_hash: PaymentHash([42; 32]),
1964                         transaction_output_index: None,
1965                 };
1966
1967                 let offered_htlc = HTLCOutputInCommitment {
1968                         offered: true,
1969                         amount_msat: 600000,
1970                         cltv_expiry: 100,
1971                         payment_hash: PaymentHash([43; 32]),
1972                         transaction_output_index: None,
1973                 };
1974
1975                 // Generate broadcaster output and received and offered HTLC outputs,  w/o anchors
1976                 builder.channel_parameters.channel_type_features = ChannelTypeFeatures::only_static_remote_key();
1977                 builder.htlcs_with_aux = vec![(received_htlc.clone(), ()), (offered_htlc.clone(), ())];
1978                 let tx = builder.build(3000, 0);
1979                 let keys = &builder.keys.clone();
1980                 assert_eq!(tx.built.transaction.output.len(), 3);
1981                 assert_eq!(tx.built.transaction.output[0].script_pubkey, get_htlc_redeemscript(&received_htlc, &ChannelTypeFeatures::only_static_remote_key(), &keys).to_v0_p2wsh());
1982                 assert_eq!(tx.built.transaction.output[1].script_pubkey, get_htlc_redeemscript(&offered_htlc, &ChannelTypeFeatures::only_static_remote_key(), &keys).to_v0_p2wsh());
1983                 assert_eq!(get_htlc_redeemscript(&received_htlc, &ChannelTypeFeatures::only_static_remote_key(), &keys).to_v0_p2wsh().to_hex_string(),
1984                                    "0020e43a7c068553003fe68fcae424fb7b28ec5ce48cd8b6744b3945631389bad2fb");
1985                 assert_eq!(get_htlc_redeemscript(&offered_htlc, &ChannelTypeFeatures::only_static_remote_key(), &keys).to_v0_p2wsh().to_hex_string(),
1986                                    "0020215d61bba56b19e9eadb6107f5a85d7f99c40f65992443f69229c290165bc00d");
1987
1988                 // Generate broadcaster output and received and offered HTLC outputs,  with anchors
1989                 builder.channel_parameters.channel_type_features = ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies();
1990                 builder.htlcs_with_aux = vec![(received_htlc.clone(), ()), (offered_htlc.clone(), ())];
1991                 let tx = builder.build(3000, 0);
1992                 assert_eq!(tx.built.transaction.output.len(), 5);
1993                 assert_eq!(tx.built.transaction.output[2].script_pubkey, get_htlc_redeemscript(&received_htlc, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(), &keys).to_v0_p2wsh());
1994                 assert_eq!(tx.built.transaction.output[3].script_pubkey, get_htlc_redeemscript(&offered_htlc, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(), &keys).to_v0_p2wsh());
1995                 assert_eq!(get_htlc_redeemscript(&received_htlc, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(), &keys).to_v0_p2wsh().to_hex_string(),
1996                                    "0020b70d0649c72b38756885c7a30908d912a7898dd5d79457a7280b8e9a20f3f2bc");
1997                 assert_eq!(get_htlc_redeemscript(&offered_htlc, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(), &keys).to_v0_p2wsh().to_hex_string(),
1998                                    "002087a3faeb1950a469c0e2db4a79b093a41b9526e5a6fc6ef5cb949bde3be379c7");
1999         }
2000
2001         #[test]
2002         fn test_finding_revokeable_output_index() {
2003                 let mut builder = TestCommitmentTxBuilder::new();
2004
2005                 // Revokeable output present
2006                 let tx = builder.build(1000, 2000);
2007                 assert_eq!(tx.built.transaction.output.len(), 2);
2008                 assert_eq!(tx.trust().revokeable_output_index(), Some(0));
2009
2010                 // Revokeable output present (but to_broadcaster_delay missing)
2011                 let tx = CommitmentTransaction { to_broadcaster_delay: None, ..tx };
2012                 assert_eq!(tx.built.transaction.output.len(), 2);
2013                 assert_eq!(tx.trust().revokeable_output_index(), None);
2014
2015                 // Revokeable output not present (our balance is dust)
2016                 let tx = builder.build(0, 2000);
2017                 assert_eq!(tx.built.transaction.output.len(), 1);
2018                 assert_eq!(tx.trust().revokeable_output_index(), None);
2019         }
2020
2021         #[test]
2022         fn test_building_to_local_justice_tx() {
2023                 let mut builder = TestCommitmentTxBuilder::new();
2024
2025                 // Revokeable output not present (our balance is dust)
2026                 let tx = builder.build(0, 2000);
2027                 assert_eq!(tx.built.transaction.output.len(), 1);
2028                 assert!(tx.trust().build_to_local_justice_tx(253, ScriptBuf::new()).is_err());
2029
2030                 // Revokeable output present
2031                 let tx = builder.build(1000, 2000);
2032                 assert_eq!(tx.built.transaction.output.len(), 2);
2033
2034                 // Too high feerate
2035                 assert!(tx.trust().build_to_local_justice_tx(100_000, ScriptBuf::new()).is_err());
2036
2037                 // Generate a random public key for destination script
2038                 let secret_key = SecretKey::from_slice(
2039                         &<Vec<u8>>::from_hex("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100")
2040                         .unwrap()[..]).unwrap();
2041                 let pubkey_hash = BitcoinPublicKey::new(
2042                         PublicKey::from_secret_key(&Secp256k1::new(), &secret_key)).wpubkey_hash().unwrap();
2043                 let destination_script = ScriptBuf::new_v0_p2wpkh(&pubkey_hash);
2044
2045                 let justice_tx = tx.trust().build_to_local_justice_tx(253, destination_script.clone()).unwrap();
2046                 assert_eq!(justice_tx.input.len(), 1);
2047                 assert_eq!(justice_tx.input[0].previous_output.txid, tx.built.transaction.txid());
2048                 assert_eq!(justice_tx.input[0].previous_output.vout, tx.trust().revokeable_output_index().unwrap() as u32);
2049                 assert!(justice_tx.input[0].sequence.is_rbf());
2050
2051                 assert_eq!(justice_tx.output.len(), 1);
2052                 assert!(justice_tx.output[0].value < 1000);
2053                 assert_eq!(justice_tx.output[0].script_pubkey, destination_script);
2054         }
2055
2056         #[test]
2057         fn test_per_commitment_storage() {
2058                 // Test vectors from BOLT 3:
2059                 let mut secrets: Vec<[u8; 32]> = Vec::new();
2060                 let mut monitor;
2061
2062                 macro_rules! test_secrets {
2063                         () => {
2064                                 let mut idx = 281474976710655;
2065                                 for secret in secrets.iter() {
2066                                         assert_eq!(monitor.get_secret(idx).unwrap(), *secret);
2067                                         idx -= 1;
2068                                 }
2069                                 assert_eq!(monitor.get_min_seen_secret(), idx + 1);
2070                                 assert!(monitor.get_secret(idx).is_none());
2071                         };
2072                 }
2073
2074                 {
2075                         // insert_secret correct sequence
2076                         monitor = CounterpartyCommitmentSecrets::new();
2077                         secrets.clear();
2078
2079                         secrets.push([0; 32]);
2080                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2081                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2082                         test_secrets!();
2083
2084                         secrets.push([0; 32]);
2085                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2086                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2087                         test_secrets!();
2088
2089                         secrets.push([0; 32]);
2090                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2091                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2092                         test_secrets!();
2093
2094                         secrets.push([0; 32]);
2095                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2096                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2097                         test_secrets!();
2098
2099                         secrets.push([0; 32]);
2100                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2101                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2102                         test_secrets!();
2103
2104                         secrets.push([0; 32]);
2105                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2106                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2107                         test_secrets!();
2108
2109                         secrets.push([0; 32]);
2110                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2111                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2112                         test_secrets!();
2113
2114                         secrets.push([0; 32]);
2115                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2116                         monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).unwrap();
2117                         test_secrets!();
2118                 }
2119
2120                 {
2121                         // insert_secret #1 incorrect
2122                         monitor = CounterpartyCommitmentSecrets::new();
2123                         secrets.clear();
2124
2125                         secrets.push([0; 32]);
2126                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
2127                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2128                         test_secrets!();
2129
2130                         secrets.push([0; 32]);
2131                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2132                         assert!(monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).is_err());
2133                 }
2134
2135                 {
2136                         // insert_secret #2 incorrect (#1 derived from incorrect)
2137                         monitor = CounterpartyCommitmentSecrets::new();
2138                         secrets.clear();
2139
2140                         secrets.push([0; 32]);
2141                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
2142                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2143                         test_secrets!();
2144
2145                         secrets.push([0; 32]);
2146                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
2147                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2148                         test_secrets!();
2149
2150                         secrets.push([0; 32]);
2151                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2152                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2153                         test_secrets!();
2154
2155                         secrets.push([0; 32]);
2156                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2157                         assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err());
2158                 }
2159
2160                 {
2161                         // insert_secret #3 incorrect
2162                         monitor = CounterpartyCommitmentSecrets::new();
2163                         secrets.clear();
2164
2165                         secrets.push([0; 32]);
2166                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2167                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2168                         test_secrets!();
2169
2170                         secrets.push([0; 32]);
2171                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2172                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2173                         test_secrets!();
2174
2175                         secrets.push([0; 32]);
2176                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
2177                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2178                         test_secrets!();
2179
2180                         secrets.push([0; 32]);
2181                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2182                         assert!(monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).is_err());
2183                 }
2184
2185                 {
2186                         // insert_secret #4 incorrect (1,2,3 derived from incorrect)
2187                         monitor = CounterpartyCommitmentSecrets::new();
2188                         secrets.clear();
2189
2190                         secrets.push([0; 32]);
2191                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("02a40c85b6f28da08dfdbe0926c53fab2de6d28c10301f8f7c4073d5e42e3148").unwrap());
2192                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2193                         test_secrets!();
2194
2195                         secrets.push([0; 32]);
2196                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("dddc3a8d14fddf2b68fa8c7fbad2748274937479dd0f8930d5ebb4ab6bd866a3").unwrap());
2197                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2198                         test_secrets!();
2199
2200                         secrets.push([0; 32]);
2201                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c51a18b13e8527e579ec56365482c62f180b7d5760b46e9477dae59e87ed423a").unwrap());
2202                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2203                         test_secrets!();
2204
2205                         secrets.push([0; 32]);
2206                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("ba65d7b0ef55a3ba300d4e87af29868f394f8f138d78a7011669c79b37b936f4").unwrap());
2207                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2208                         test_secrets!();
2209
2210                         secrets.push([0; 32]);
2211                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2212                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2213                         test_secrets!();
2214
2215                         secrets.push([0; 32]);
2216                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2217                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2218                         test_secrets!();
2219
2220                         secrets.push([0; 32]);
2221                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2222                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2223                         test_secrets!();
2224
2225                         secrets.push([0; 32]);
2226                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2227                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
2228                 }
2229
2230                 {
2231                         // insert_secret #5 incorrect
2232                         monitor = CounterpartyCommitmentSecrets::new();
2233                         secrets.clear();
2234
2235                         secrets.push([0; 32]);
2236                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2237                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2238                         test_secrets!();
2239
2240                         secrets.push([0; 32]);
2241                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2242                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2243                         test_secrets!();
2244
2245                         secrets.push([0; 32]);
2246                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2247                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2248                         test_secrets!();
2249
2250                         secrets.push([0; 32]);
2251                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2252                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2253                         test_secrets!();
2254
2255                         secrets.push([0; 32]);
2256                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
2257                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2258                         test_secrets!();
2259
2260                         secrets.push([0; 32]);
2261                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2262                         assert!(monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).is_err());
2263                 }
2264
2265                 {
2266                         // insert_secret #6 incorrect (5 derived from incorrect)
2267                         monitor = CounterpartyCommitmentSecrets::new();
2268                         secrets.clear();
2269
2270                         secrets.push([0; 32]);
2271                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2272                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2273                         test_secrets!();
2274
2275                         secrets.push([0; 32]);
2276                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2277                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2278                         test_secrets!();
2279
2280                         secrets.push([0; 32]);
2281                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2282                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2283                         test_secrets!();
2284
2285                         secrets.push([0; 32]);
2286                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2287                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2288                         test_secrets!();
2289
2290                         secrets.push([0; 32]);
2291                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("631373ad5f9ef654bb3dade742d09504c567edd24320d2fcd68e3cc47e2ff6a6").unwrap());
2292                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2293                         test_secrets!();
2294
2295                         secrets.push([0; 32]);
2296                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("b7e76a83668bde38b373970155c868a653304308f9896692f904a23731224bb1").unwrap());
2297                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2298                         test_secrets!();
2299
2300                         secrets.push([0; 32]);
2301                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2302                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2303                         test_secrets!();
2304
2305                         secrets.push([0; 32]);
2306                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2307                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
2308                 }
2309
2310                 {
2311                         // insert_secret #7 incorrect
2312                         monitor = CounterpartyCommitmentSecrets::new();
2313                         secrets.clear();
2314
2315                         secrets.push([0; 32]);
2316                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2317                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2318                         test_secrets!();
2319
2320                         secrets.push([0; 32]);
2321                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2322                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2323                         test_secrets!();
2324
2325                         secrets.push([0; 32]);
2326                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2327                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2328                         test_secrets!();
2329
2330                         secrets.push([0; 32]);
2331                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2332                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2333                         test_secrets!();
2334
2335                         secrets.push([0; 32]);
2336                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2337                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2338                         test_secrets!();
2339
2340                         secrets.push([0; 32]);
2341                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2342                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2343                         test_secrets!();
2344
2345                         secrets.push([0; 32]);
2346                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("e7971de736e01da8ed58b94c2fc216cb1dca9e326f3a96e7194fe8ea8af6c0a3").unwrap());
2347                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2348                         test_secrets!();
2349
2350                         secrets.push([0; 32]);
2351                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("05cde6323d949933f7f7b78776bcc1ea6d9b31447732e3802e1f7ac44b650e17").unwrap());
2352                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
2353                 }
2354
2355                 {
2356                         // insert_secret #8 incorrect
2357                         monitor = CounterpartyCommitmentSecrets::new();
2358                         secrets.clear();
2359
2360                         secrets.push([0; 32]);
2361                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("7cc854b54e3e0dcdb010d7a3fee464a9687be6e8db3be6854c475621e007a5dc").unwrap());
2362                         monitor.provide_secret(281474976710655, secrets.last().unwrap().clone()).unwrap();
2363                         test_secrets!();
2364
2365                         secrets.push([0; 32]);
2366                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c7518c8ae4660ed02894df8976fa1a3659c1a8b4b5bec0c4b872abeba4cb8964").unwrap());
2367                         monitor.provide_secret(281474976710654, secrets.last().unwrap().clone()).unwrap();
2368                         test_secrets!();
2369
2370                         secrets.push([0; 32]);
2371                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("2273e227a5b7449b6e70f1fb4652864038b1cbf9cd7c043a7d6456b7fc275ad8").unwrap());
2372                         monitor.provide_secret(281474976710653, secrets.last().unwrap().clone()).unwrap();
2373                         test_secrets!();
2374
2375                         secrets.push([0; 32]);
2376                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("27cddaa5624534cb6cb9d7da077cf2b22ab21e9b506fd4998a51d54502e99116").unwrap());
2377                         monitor.provide_secret(281474976710652, secrets.last().unwrap().clone()).unwrap();
2378                         test_secrets!();
2379
2380                         secrets.push([0; 32]);
2381                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("c65716add7aa98ba7acb236352d665cab17345fe45b55fb879ff80e6bd0c41dd").unwrap());
2382                         monitor.provide_secret(281474976710651, secrets.last().unwrap().clone()).unwrap();
2383                         test_secrets!();
2384
2385                         secrets.push([0; 32]);
2386                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("969660042a28f32d9be17344e09374b379962d03db1574df5a8a5a47e19ce3f2").unwrap());
2387                         monitor.provide_secret(281474976710650, secrets.last().unwrap().clone()).unwrap();
2388                         test_secrets!();
2389
2390                         secrets.push([0; 32]);
2391                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("a5a64476122ca0925fb344bdc1854c1c0a59fc614298e50a33e331980a220f32").unwrap());
2392                         monitor.provide_secret(281474976710649, secrets.last().unwrap().clone()).unwrap();
2393                         test_secrets!();
2394
2395                         secrets.push([0; 32]);
2396                         secrets.last_mut().unwrap()[0..32].clone_from_slice(&<Vec<u8>>::from_hex("a7efbc61aac46d34f77778bac22c8a20c6a46ca460addc49009bda875ec88fa4").unwrap());
2397                         assert!(monitor.provide_secret(281474976710648, secrets.last().unwrap().clone()).is_err());
2398                 }
2399         }
2400 }